Add missing solution items

These files exist in the repo and are useful to have in the solution, so that they may contribute results to search operations.

GitExtensions.sln

@@ -6,6 +6,7 @@ MinimumVisualStudioVersion = 15.0.27130.0
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Plugins", "Plugins", "{3D5CA0E0-EF51-4488-A8B7-86CC330D7AD8}"
 	ProjectSection(SolutionItems) = preProject
 		Plugins\Directory.Build.props = Plugins\Directory.Build.props
+		Plugins\Directory.Build.targets = Plugins\Directory.Build.targets
 	EndProjectSection
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Statistics", "Statistics", "{AF6D7B1B-FAF6-4793-AC05-00C63A5BC0F5}"
@@ -120,6 +121,9 @@ EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AppVeyorIntegration", "Plugins\BuildServerIntegration\AppVeyorIntegration\AppVeyorIntegration.csproj", "{39228D7F-9239-4A2D-8A6F-4D0F7DEB9178}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "UnitTests", "UnitTests", "{020F800B-9170-4BB3-83C9-FCF83596D83C}"
+	ProjectSection(SolutionItems) = preProject
+		UnitTests\Directory.Build.props = UnitTests\Directory.Build.props
+	EndProjectSection
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "GitCommands.Tests", "UnitTests\GitCommands.Tests\GitCommands.Tests.csproj", "{E0BC2504-6BBB-4197-95EA-A2F7542BC15F}"
 EndProject
@@ -157,6 +161,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		PrivacyPolicy.md = PrivacyPolicy.md
 		PrivacyPolicy.rtf = PrivacyPolicy.rtf
 		README.md = README.md
+		Solution.Versions.props = Solution.Versions.props
 	EndProjectSection
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "scripts", "scripts", "{472B72D9-9336-4C8B-A199-300F0CA7669E}"