updated for vs2013, added universal target libprotobuf-lite

1. Fixes to make libs and protoc compile with VS2013
2. Added project for Windows 8.1/Phone 8.1 Universal libprotobuf-lite
3. Tests/test-plugins projects do not compile and I am not sure what to do about it (the code  seems completely iincompatible with Visual C++ 2013). Someone with more familiarity with the code can at least use the new solution to figure that out.

Since the Visual Studio project  in the repository  was for 2008, I figure this at least gets things started on the road to being up to date.