Updated projects for Visual Studio 2010, 2012 and 2013
* 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
Added a README file regarding WinRT support
To note, this file is currently formatted with CRLF line endings, rather than
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