Added missing files to SDL2 project
Added missing Visual Studio 2008 tests to the solution
Added output paths which match the 2010+ projects
Added SDL project references instead of old style project dependencies
Removed post-build copy step and added data files to projects
* Test programs use project references instead of hard-coding SDL library dependencies
* Test data files are copied only when needed.
* Copying SDL2.dll is no longer necessary
* Fixed /SAFESEH warning
* Fixed attempted rebuild of SDL every time a test program is run
