update sdl2 to release https://github.com/spurious/SDL-mirror/tree/release-2.0.14

Engine/lib/sdl/docs/README.md

@@ -0,0 +1,63 @@
+Simple DirectMedia Layer {#mainpage}
+========================
+
+                                  (SDL)
+
+                                Version 2.0
+
+---
+http://www.libsdl.org/
+
+Simple DirectMedia Layer is a cross-platform development library designed
+to provide low level access to audio, keyboard, mouse, joystick, and graphics
+hardware via OpenGL and Direct3D. It is used by video playback software,
+emulators, and popular games including Valve's award winning catalog
+and many Humble Bundle games.
+
+SDL officially supports Windows, Mac OS X, Linux, iOS, and Android.
+Support for other platforms may be found in the source code.
+
+SDL is written in C, works natively with C++, and there are bindings 
+available for several other languages, including C# and Python.
+
+This library is distributed under the zlib license, which can be found
+in the file "COPYING.txt".
+
+The best way to learn how to use SDL is to check out the header files in
+the "include" subdirectory and the programs in the "test" subdirectory.
+The header files and test programs are well commented and always up to date.
+
+More documentation and FAQs are available online at [the wiki](http://wiki.libsdl.org/)
+
+- [Android](README-android.md)
+- [CMake](README-cmake.md)
+- [DirectFB](README-directfb.md)
+- [DynAPI](README-dynapi.md)
+- [Emscripten](README-emscripten.md)
+- [Gesture](README-gesture.md)
+- [Mercurial](README-hg.md)
+- [iOS](README-ios.md)
+- [Linux](README-linux.md)
+- [OS X](README-macosx.md)
+- [Native Client](README-nacl.md)
+- [Pandora](README-pandora.md)
+- [Supported Platforms](README-platforms.md)
+- [Porting information](README-porting.md)
+- [PSP](README-psp.md)
+- [Raspberry Pi](README-raspberrypi.md)
+- [Touch](README-touch.md)
+- [WinCE](README-wince.md)
+- [Windows](README-windows.md)
+- [WinRT](README-winrt.md)
+
+If you need help with the library, or just want to discuss SDL related
+issues, you can join the [developers mailing list](http://www.libsdl.org/mailing-list.php)
+
+If you want to report bugs or contribute patches, please submit them to
+[bugzilla](https://bugzilla.libsdl.org/)
+
+Enjoy!
+
+
+Sam Lantinga <mailto:slouken@libsdl.org>
+