Merge pull request #1726 from jcansdale/fixes/1725-build-2017-target-2015

Use VS2015 SDK tasks when StartProgram is VS2015

Author: grokys

src/GitHub.VisualStudio/GitHub.VisualStudio.csproj

@@ -1,6 +1,13 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="14.0">
   <Import Project="..\..\packages\LibGit2Sharp.NativeBinaries.1.0.164\build\LibGit2Sharp.NativeBinaries.props" Condition="Exists('..\..\packages\LibGit2Sharp.NativeBinaries.1.0.164\build\LibGit2Sharp.NativeBinaries.props')" />
+  
+  <!-- When StartProgram is set to Visual Studio 2015 in .user file, install extension in the same version  -->
+  <Import Project="GitHub.VisualStudio.csproj.user" Condition=" Exists('GitHub.VisualStudio.csproj.user') " />
+  <PropertyGroup Condition=" $(StartProgram.Contains('Microsoft Visual Studio 14.0')) ">
+    <VisualStudioVersion>14.0</VisualStudioVersion>
+  </PropertyGroup>
+  
   <Import Project="..\..\packages\Microsoft.VisualStudio.Sdk.BuildTasks.14.0.14.0.215\build\Microsoft.VisualStudio.Sdk.BuildTasks.14.0.props" Condition="'$(VisualStudioVersion)' == '14.0' And Exists('..\..\packages\Microsoft.VisualStudio.Sdk.BuildTasks.14.0.14.0.215\build\Microsoft.VisualStudio.Sdk.BuildTasks.14.0.props')" />
   <Import Project="..\..\packages\Microsoft.VSSDK.BuildTools.15.0.26201\build\Microsoft.VSSDK.BuildTools.props" Condition="'$(VisualStudioVersion)' == '15.0' And Exists('..\..\packages\Microsoft.VSSDK.BuildTools.15.0.26201\build\Microsoft.VSSDK.BuildTools.props')" />
   <PropertyGroup>
@@ -27,7 +34,7 @@
     <RootNamespace>GitHub.VisualStudio</RootNamespace>
     <AssemblyName>GitHub.VisualStudio</AssemblyName>
     <StartAction>Program</StartAction>
-    <StartProgram>$(DevEnvDir)\devenv.exe</StartProgram>
+    <StartProgram Condition="' $(StartProgram)' == '' ">$(DevEnvDir)\devenv.exe</StartProgram>
     <StartArguments>/rootsuffix Exp</StartArguments>
     <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>