new 'xvmc' branch of intel video driver

[Zhenyu Wang]

The aim of the new 'xvmc' branch is to deprecate origin
'xvmc-i915' branch with lot of cleanups and new framework
inside driver to add supports for more hardware media decode
drivers in future. It also has changes that affect users.

The most noteable is that the origin libI915XvMC.so is replaced
by a single libIntelXvMC.so entry to be used on different
chipsets for different hardware decoders. Although currently
there's only one decoder for MPEG MC on 915/945/G33 series.
So you should change lib path in your XvMCConfig file.

New driver option "XvMC" and config option can be used to disable
XvMC feature in the driver. It turns on by default.

Welcome to test and send issues to me.

Thanks.