Reworked PCI MMIO command buffer parser, and imported code from the Mesa

Reworked PCI MMIO command buffer parser, and imported code from the Mesa
    driver. It can now handle the 3D OpenGL commands from the Mesa
    unichrome driver.
Added vsync frequency detection support. This will be used in the future
    for XvMC and better frame timing.
Bumped minor version number and driver date.