[Libva] Master sync with libva31 branch

[Yuan, Shengquan]

Now five patches from Gwenole
(http://www.splitted-desktop.com/~gbeauchesne/libva/patches/ 104,
301,302,303,304) were added into master branch. I also combined
vaPutImage/vaPutImage2, vaAssociatedSubpicture/vaAssociatedSubpicture2
and bumped VAAPI version to 0.31 (the new SONAME is libva.so.1 now).
The old libva30 was put into "libva30" branch. Please help to see if
my change will break something.

Besides these changes, I also want to remove "context" from
vaSyncSurface API, since I think sometimes a surface may not associate
with a context, but we want to get its status. If nobody disagree with
it, I will check in the change.

Now comparing "master" with "libva31" branch, master doesn't integrate
 Gwenole's patch 202_split_libva.patch which splits libva.so into
libva-core.so and libva-x11.so. Personally I like one single libva.so
because currently every VA API relies on a "DISPLAY" which depends on
libva-x11, that means libva-core.so can't be used individually.  Is
there a strong reason we must splite them, code complexity? or is
there any idea to support decode/encode even without a DISPLAY/X
environment (libva-null, libva-fb?), and only need a X when display
something?

Thanks
Austin