project: reorganize the structure of the project.

* remove dotnet-tool.json because the project does not rely on any dotnet tools.
* remove Directory.Build.props because the solution has only one project.
* move src/SourceGit to src. It's not needed to put all sources into a subfolder of src since there's only one project.

src/Views/SelfUpdate.axaml

@@ -0,0 +1,153 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:m="using:SourceGit.Models"
+        xmlns:vm="using:SourceGit.ViewModels"
+        xmlns:sys="clr-namespace:System;assembly=mscorlib"
+        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+        x:Class="SourceGit.Views.SelfUpdate"
+        x:DataType="vm:SelfUpdate"
+        Title="{DynamicResource Text.SelfUpdate.Title}"
+        Icon="/App.ico"
+        Background="Transparent"
+        SizeToContent="WidthAndHeight"
+        CanResize="False"
+        WindowStartupLocation="CenterOwner"
+        ExtendClientAreaToDecorationsHint="True"
+        ExtendClientAreaChromeHints="NoChrome"
+        SystemDecorations="{OnPlatform Full, Linux=None}">
+  <Grid RowDefinitions="Auto,*" Margin="{OnPlatform 0, Linux=6}">
+    <!-- Custom window shadow for Linux -->
+    <Border Grid.Row="0" Grid.RowSpan="2"
+            Background="{DynamicResource Brush.Window}"
+            Effect="drop-shadow(0 0 6 #A0000000)"
+            IsVisible="{OnPlatform False, Linux=True}"/>
+
+    <!-- TitleBar -->
+    <Grid Grid.Row="0" ColumnDefinitions="Auto,*,Auto" Height="30">
+      <Border Grid.Column="0" Grid.ColumnSpan="3"
+              Background="{DynamicResource Brush.TitleBar}"
+              BorderThickness="0,0,0,1" BorderBrush="{DynamicResource Brush.Border0}"
+              PointerPressed="BeginMoveWindow"/>
+
+      <Path Grid.Column="0"
+            Width="14" Height="14"
+            Margin="10,0,0,0"
+            Data="{StaticResource Icons.SoftwareUpdate}"
+            IsVisible="{OnPlatform True, macOS=False}"/>
+
+      <Grid Grid.Column="0" Classes="caption_button_box" Margin="2,4,0,0" IsVisible="{OnPlatform False, macOS=True}">
+        <Button Classes="caption_button_macos" Click="CloseWindow">
+          <Grid>
+            <Ellipse Fill="{DynamicResource Brush.MacOS.Close}"/>
+            <Path Height="6" Width="6" Stretch="Fill" Fill="#404040" Stroke="#404040" StrokeThickness="1" Data="{StaticResource Icons.Window.Close}"/>
+          </Grid>
+        </Button>
+      </Grid>
+
+      <TextBlock Grid.Column="0" Grid.ColumnSpan="3"
+                 Classes="bold"
+                 Text="{DynamicResource Text.SelfUpdate.Title}"
+                 HorizontalAlignment="Center" VerticalAlignment="Center"
+                 IsHitTestVisible="False"/>
+
+      <Button Grid.Column="2"
+              Classes="caption_button"
+              Click="CloseWindow"
+              IsVisible="{OnPlatform True, macOS=False}">
+        <Path Data="{StaticResource Icons.Window.Close}"/>
+      </Button>
+    </Grid>
+
+    <!-- Body -->
+    <Grid Grid.Row="1" Background="{DynamicResource Brush.Window}">
+      <ContentControl Content="{Binding Data}">
+        <ContentControl.DataTemplates>
+          <DataTemplate DataType="m:Version">
+            <StackPanel Orientation="Vertical" Margin="16,8">
+              <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,8">
+                <Path Width="14" Height="14" Data="{StaticResource Icons.Info}" Fill="Green"/>
+                <TextBlock Margin="8,0,0,0" FontWeight="Bold" FontSize="14" Text="{DynamicResource Text.SelfUpdate.Available}"/>
+                <Border Margin="4,0,0,0" Height="20" CornerRadius="10" Background="{DynamicResource Brush.Accent1}" Effect="drop-shadow(0 0 6 #40000000)">
+                  <TextBlock Classes="monospace" Margin="8,0" Text="{Binding TagName}" FontSize="12" Foreground="White"/>
+                </Border>
+              </StackPanel>
+
+              <TextBox IsReadOnly="True"
+                       TextWrapping="Wrap"
+                       ScrollViewer.VerticalScrollBarVisibility="Auto"
+                       MaxWidth="500" MaxHeight="400"
+                       Margin="0,8" Padding="0"
+                       VerticalContentAlignment="Top"
+                       Text="{Binding Body}"/>
+
+              <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
+                <Button Classes="flat primary"
+                        Height="30"
+                        Click="GotoDownload"
+                        HorizontalContentAlignment="Center"
+                        VerticalContentAlignment="Center">
+                  <StackPanel Orientation="Horizontal">
+                    <Path Width="12" Height="12" Data="{StaticResource Icons.Pull}"/>
+                    <TextBlock Text="{DynamicResource Text.SelfUpdate.GotoDownload}" Margin="8,0,0,0"/>
+                  </StackPanel>
+                </Button>
+
+                <Button Classes="flat"
+                        Height="30"
+                        Margin="8,0,0,0"
+                        Click="IgnoreThisVersion"
+                        HorizontalContentAlignment="Center"
+                        VerticalContentAlignment="Center">
+                  <StackPanel Orientation="Horizontal">
+                    <Path Width="12" Height="12" Data="{StaticResource Icons.File.Ignore}"/>
+                    <TextBlock Text="{DynamicResource Text.SelfUpdate.IgnoreThisVersion}" Margin="8,0,0,0"/>
+                  </StackPanel>
+                </Button>
+              </StackPanel>
+            </StackPanel>
+          </DataTemplate>
+
+          <DataTemplate DataType="sys:Exception">
+            <StackPanel Orientation="Vertical" Margin="16,8">
+              <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
+                <Path Width="14" Height="14" Data="{StaticResource Icons.Error}" Fill="Red"/>
+                <TextBlock Margin="8,0,0,0" FontWeight="Bold" FontSize="14" Text="{DynamicResource Text.SelfUpdate.Error}"/>
+              </StackPanel>
+
+              <TextBlock Text="{Binding Message}" MaxWidth="500" TextWrapping="Wrap" Margin="0,8"/>
+
+              <Button Classes="flat primary"
+                      Height="30"
+                      Margin="4,0"
+                      Click="CloseWindow"
+                      Content="{DynamicResource Text.Close}"
+                      HorizontalAlignment="Center"
+                      HorizontalContentAlignment="Center"
+                      VerticalContentAlignment="Center"/>
+            </StackPanel>
+          </DataTemplate>
+
+          <DataTemplate DataType="m:AlreadyUpToDate">
+            <StackPanel Orientation="Vertical" Margin="16,8">
+              <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,8">
+                <Path Width="14" Height="14" Data="{StaticResource Icons.Info}" Fill="Green"/>
+                <TextBlock Margin="8,0,0,0" Text="{DynamicResource Text.SelfUpdate.UpToDate}"/>
+              </StackPanel>              
+
+              <Button Classes="flat primary"
+                      Height="30"
+                      Margin="4,0"
+                      Click="CloseWindow"
+                      Content="{DynamicResource Text.Close}"
+                      HorizontalAlignment="Center"
+                      HorizontalContentAlignment="Center"
+                      VerticalContentAlignment="Center"/>
+            </StackPanel>
+          </DataTemplate>
+        </ContentControl.DataTemplates>
+      </ContentControl>
+    </Grid>
+  </Grid>
+</Window>