redist_init_2 SetEnv task breaks PATH (missing semicolon)

[dakotahawkins]

Example repository here: https://github.com/dakotahawkins/TestCoApp

Built packages are in the "NuGetPackages" directory, main solution is "TestCoApp.sln". Two custom targets print the PATH environment variable before and after CoAppDLL_redist_init_2:

1>Path_Before_CoAppDLL_redist_init_2:
1>  PATH:
1>      C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer\NativeBinaries/x86; ...
1>Path_After_CoAppDLL_redist_init_2:
1>  PATH:
1>      D:\TestCoApp\packages\CoAppDLL.redist.1.0\build\native\../..//build/native/bin/v120\Win32\Debug\dynamicC:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer\NativeBinaries/x86; ...