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/ViewModels/GitFlowFinish.cs

@@ -0,0 +1,55 @@
+using System.Threading.Tasks;
+
+namespace SourceGit.ViewModels
+{
+    public class GitFlowFinish : Popup
+    {
+        public Models.Branch Branch => _branch;
+        public bool IsFeature => _type == Models.GitFlowBranchType.Feature;
+        public bool IsRelease => _type == Models.GitFlowBranchType.Release;
+        public bool IsHotfix => _type == Models.GitFlowBranchType.Hotfix;
+
+        public bool KeepBranch
+        {
+            get;
+            set;
+        } = false;
+
+        public GitFlowFinish(Repository repo, Models.Branch branch, Models.GitFlowBranchType type)
+        {
+            _repo = repo;
+            _branch = branch;
+            _type = type;
+            View = new Views.GitFlowFinish() { DataContext = this };
+        }
+
+        public override Task<bool> Sure()
+        {
+            _repo.SetWatcherEnabled(false);
+            return Task.Run(() =>
+            {
+                var branch = _branch.Name;
+                switch (_type)
+                {
+                    case Models.GitFlowBranchType.Feature:
+                        branch = branch.Substring(_repo.GitFlow.Feature.Length);
+                        break;
+                    case Models.GitFlowBranchType.Release:
+                        branch = branch.Substring(_repo.GitFlow.Release.Length);
+                        break;
+                    default:
+                        branch = branch.Substring(_repo.GitFlow.Hotfix.Length);
+                        break;
+                }
+
+                var succ = new Commands.GitFlow(_repo.FullPath).Finish(_type, branch, KeepBranch);
+                CallUIThread(() => _repo.SetWatcherEnabled(true));
+                return succ;
+            });
+        }
+
+        private readonly Repository _repo = null;
+        private readonly Models.Branch _branch = null;
+        private readonly Models.GitFlowBranchType _type = Models.GitFlowBranchType.None;
+    }
+}