[cogl] (16 commits) Created branch wip/pbo-read-pixels

[Neil Roberts <nroberts src gnome org>]

The branch 'wip/pbo-read-pixels' was created.

Summary of new commits:

  fab4ec8... Add a conformance test for reading back an RGBA texture as 
  1a2c6e2... Assert that we get a valid format in pixel_format_to_gl{,es
  2d944e7... Avoid making up the format COGL_PIXEL_FORMAT_A_8_PRE
  6253b3e... bitmap-fallback: Support converting all pixel format types
  2099e88... tests: Test reading all pixel formats
  535b3d1... tests: Add a test which writes all pixel formats
  52fd452... bitmap: Remove the split between 'image library' and 'fallb
  a2d9a5f... _cogl_bitmap_convert: Also handle premult conversions
  00da844... bitmap: Add a function to convert into an existing buffer
  e50f7f7... cogl-buffer: Create the buffer store when bound
  96a658b... Add a public cogl_framebuffer_read_pixels_into_bitmap
  4cb1c0c... Change API so that CoglPixelBuffer no longer knows its w/h/
  05b1752... Make _cogl_bitmap_get_{width,height,format,rowstride} publi
  16c4812... Add the missing cast macros for some buffer objects
  f5c75f1... cogl-bitmap: Add a public accessor for the underlying pixel
  b4ffd1d... Port the test-pixel-buffer test