First demo application.
Use SDL, libktx, and NDK's sample "hello-gl2" to build a start code-base.

Known issue:
will crash on early PowerVR SGX GPUs (for example, SGX 531, released on Oct 2006, earlier than the release date of OpenGL ES 2.0 standard, March 2007!). Newer PowerVR GPUs (for example, SGX 544), and some other GPUs I have tested are all working fine.
See: http://forum.imgtec.com/discussion/2232/corrupt-etc1-textures
add Microsoft Visual Studio 2013 project. now we can run our program under Microsoft Windows.