fix extension deployment and add explainatory comment

src/Compilers/Extension/CompilerExtension.csproj

@@ -18,6 +18,7 @@
     <CopyOutputSymbolsToOutputDirectory>true</CopyOutputSymbolsToOutputDirectory>
     <VSSDKTargetPlatformRegRootSuffix>RoslynDev</VSSDKTargetPlatformRegRootSuffix>
     <RoslynProjectType>Vsix</RoslynProjectType>
+    <IncludeCopyLocalReferencesInVSIXContainer>false</IncludeCopyLocalReferencesInVSIXContainer> 
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'" />

src/Compilers/Extension/SetGlobalGlobalPropertiesForCPS.cs

@@ -22,6 +22,8 @@ public SetGlobalGlobalPropertiesForCPS(IProjectService projectService)
 
         public override Task<IImmutableDictionary<string, string>> GetGlobalPropertiesAsync(CancellationToken cancellationToken)
         {
+            // Currently the SolutionExists context will always occur before CPS calls this class
+            // If this behavior ever changes we will need to modify this class.
             return CompilerPackage.RoslynHive != null
                 ? Task.FromResult<IImmutableDictionary<string, string>>(Empty.PropertiesMap.Add("RoslynHive", CompilerPackage.RoslynHive))
                 : Task.FromResult<IImmutableDictionary<string, string>>(Empty.PropertiesMap);