signed, VS2012 support, azure issue fix, packages

- Library is now signed with key.snk, 
- Solution and project files upgraded to VS2012, 
- Package dependencies updated, fixed issue described here:
http://social.msdn.microsoft.com/Forums/windowsazure/en-US/9c5d40dc-8795-49db-8889-964e1acd8832/azure-diagnostics-access-to-the-path-guidmswapdlock-is-denied?forum=windowsazuremanagement