Update CONTRIBUTING.md

Made spelling change to git-flow instructions
Updated .bat file references to .cmd file extensions
Changed text so users change to the Build directory before running the .cmd files.  Running from elsewhere gave an MSBUILD error that the Build.proj file couldn't be found.
Merge pull request #97 from scpeterson/master

Update CONTRIBUTING.md
Fixes #101
Use nuget for MVC 4 references
Added CommonServiceLocator.WindsorAdapter to dependency packages
Merge branch 'kad0xf-#101' into 2.2RC
Merge branch 'kad0xf-Use-nuget-for-MVC-4-references' into 2.2RC
Version 2.2 RC
Merge remote-tracking branch 'upstream/master'