Add support for reading framebuffers to memory.

Signed-off-by: arnastia <arnastia@gmail.com>
Small fix for debugger (GWL_WNDPROC isn't defined for 64bits, wouldn't compile).
Change PSPPointer function name Valid to IsValid.

Improves readability and shows intent better.
Fix some signed/unsigned mismatch warnings in __sceAudio.cpp.
Merge pull request #2464 from lioncash/master

Change PSPPointer function name Valid to IsValid. Also fix some signed/unsigned mismatch warnings in __sceAudio.cpp
Merge remote-tracking branch 'upstream/master' into framebuffers-to-mem
Add FramebuffersToMem option to allow disabling of reading framebuffer contents to memory (defaults to false).
Blit framebuffers using screen aligned quads (buggy);

Implement asynchronous framebuffer readback for OpenGL and optional CPU-side pixel format conversion (needs optimization);
Add OpenGL ES support (untested).
Merge branch 'framebuffers-to-mem'