Add ProjectGuid

This is needed otherwise it triggers this: http://social.msdn.microsoft.com/Forums/vstudio/en-US/5777b517-e935-4905-bf76-8f38d6d8913a/the-project-file-has-been-renamed-or-is-no-longer-in-the-solution-after-moving-solution?forum=vcgeneral
Merge pull request #1 from Gargaj/patch-1

Add ProjectGuid