Workaround for negative overlay position bug

Negative Y coordinates lead to shifted output picture due to
some bug either in the kernel driver or in the hardware,
so we just cut off the part with negative Y position.
Fix waiting condition for basic bits read
Add function to get VE version
Add buffers for VE version 0x1625

VE version 0x1625 needs two extra buffers for h264 decoding,
persumably for some sort of line cache.
Return useful values in query functions instead of error

Most of them return is_supported false now, because most features
aren't supported yet.
Make most debug messages print only once

This stops messages about not implemented functions flooding
the console.
Add more h264 decoding parameters
Add support for custom h264 scaling lists
Support vdp_video_surface_put_bits_y_cb_cr.

Tested in MPlayer to work with uncompressed YV12, NV12, YUYV and UYUV.
Allows using VDPAU also for videos that have no hardware decoder support.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Fix Makefile
Merge branch 'master' of https://github.com/jemk/libvdpau-sunxi