Ensure uniform and optimal drawing performance on MeeGo

From http://www.gitorious.com/meego-graphics/meego-graphics/blobs/master/README

The graphics system is based on the existing GL functionalities in Qt.
It uses a standard GL-accelerated window surface (QGLWindowSurface) but
for standard pixmaps it uses raster-backed image data. This is because
the QGLPixmapData's from the opengl/ module are not really ready for
prime time on EGL.

Additionally, this graphics system contains some functionalities and
features that are specific to the meego platform and can be detected on
runtime. The application/toolkit is expected to detect the meego graphics
system usage and act accordingly. Currently, the unique features offered
by the meegographicssystem are:

• Efficient sharing of graphical resources via EGL shared images.
• Dynamic switch to raster graphics system via standard Qt API.
• Automatic migration of shared QPixmaps between GL <=> raster

Features under development include:

• Live-streamed textures for fast offscreen rendering.
• Widget for automatic, hw-supported surface scaling.