Created Issue: Build Fails - SkipStrongNames Reports Conflicted Setting [950]

I clone the repo, build it according to instructions, and get the following error:

> Unit tests will not run correctly unless SkipStrongNames is Enabled.
> Current status: Disabled.
> Run 'build /t:EnableSkipStrongNames' to fix the problem.

I build the EnableSkipStrongNames target and get this strange error

> Skip Strong Names is already enabled.
> SkipStrongNames: Disabled

I've attached the output of ```build /v:n /t:EnableSkipStrongNames``` to this issue.

__Steps to Reproduce - Attempt 1__
1. Open "VS2012 x86 Native Tools Command Prompt"
1. Run git clone https://git01.codeplex.com/entityframework
1. Clear my .NuGet cache at ```%LocalAppData%\NuGet\Cache```
1. Run ```build /t:RestorePackages```
1. Run ```build /t:EnableSkipStrongNames```
1. Run ```build```

__Steps to Reproduce - Attempt 2__
1. Open "VS2012 x86 Native Tools Command Prompt"
1. Run git clone https://git01.codeplex.com/entityframework
1. Clear my .NuGet cache at ```%LocalAppData%\NuGet\Cache```
1. Run ```build /t:RestorePackages```
1. Run ```build```

__Machine Information__
* Windows 7 64-bit
* Installed Microsoft Visual Studio Versions
* 2010 Ultimate
* 2012 Ultimate
* Entries in HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP
* CDF
* v2.0.50727
* v3.0
* v3.5
* v4
* v4.0