Merge pull request #1 from TooTallNate/master

Update to latest on TooTallNate's repository
Handle when both VS2010 and VS2012 are installed

When both versions are present, attempt to use the command prompt to
determine which one should be set.

The command prompt for VS2012 set the environment variable to:

VisualStudioVersion=11.0

This environment variable is absent in the VS2010 command prompts.

Also, presumably the checkVCExpress function not setting hasVCExpress
was an oversight.
Merge pull request #300 from icosahedron/master

Handle when both VS2010 and VS2012 Express are installed