Adjust for native window API changes for sync fence support

Signed-off-by: Simon Busch <morphis@gravedo.de>
Cleanup offscreen rendering code

Signed-off-by: Simon Busch <morphis@gravedo.de>
Implement new native window API method setBufferCount

Signed-off-by: Simon Busch <morphis@gravedo.de>
Link against libhybris-eglplatformcommon

Signed-off-by: Simon Busch <morphis@gravedo.de>
Mark buffer as still used when it's returned to our native window implementation

Signed-off-by: Simon Busch <morphis@gravedo.de>
Implemented dynamic buffer count support.

 * one drawback is that the "bufferCount()" method isn't static anymore, so the HostWindowOpenGLHybris has to pick a number itself.

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>