feature<SubTree>: supports git subtree feature

src/Views/Popups/SubTreePush.xaml.cs

@@ -0,0 +1,41 @@
+using System.Threading.Tasks;
+using System.Windows.Controls;
+
+namespace SourceGit.Views.Popups {
+    /// <summary>
+    ///     推送
+    /// </summary>
+    public partial class SubTreePush : Controls.PopupWidget {
+        private string repo;
+        private Models.SubTree subtree;
+
+        public string Branch {
+            get { return subtree.Branch; }
+            set { subtree.Branch = value; }
+        }
+
+        public SubTreePush(string repo, Models.SubTree subtree) {
+            this.repo = repo;
+            this.subtree = subtree;
+            InitializeComponent();
+            txtPrefix.Text = subtree.Prefix;
+            txtSource.Text = subtree.Remote;
+        }
+
+        public override string GetTitle() {
+            return App.Text("SubTreePullOrPush.Push");
+        }
+
+        public override Task<bool> Start() {
+            txtBranch.GetBindingExpression(TextBox.TextProperty).UpdateSource();
+            if (Validation.GetHasError(txtBranch)) return null;
+
+            return Task.Run(() => {
+                Models.Watcher.SetEnabled(repo, false);
+                new Commands.SubTree(repo).Push(subtree.Prefix, subtree.Remote, Branch, UpdateProgress);
+                Models.Watcher.SetEnabled(repo, true);
+                return true;
+            });
+        }
+    }
+}