[WIN32][WASAPI] created a drain method.
[WIN32][DirectSound] added fake entry default and make sink understand it.
Merge pull request #150 from wsoltys/sledgehammer

[WIN32] added Drain for WASAPI and default entry for DirectSound
Fixes potential NULL pointer dereference.
Merge pull request #151 from t-nelson/viz_crash_fix

Viz crash fix
renderer: use fence for determination when a buffer is ready for reuse
videoplayer: adapt lateness detection and dropping to buffering
video player: present correct pts to user for a/v sync (after buffering in renderer)
videoplayer: some rework and documentation
vdpau: redesign
vdpau: make interop gl default and remove setting, rename and intvert interop yuv
vdpau: drop studio level conversion
vdpau: observe ffmpeg tags for color space
vdpau: switch off de-interlacing on ff
vdpau: fix mp4 part2 decoding, activate by default
vdpau: re-add limited range conversion
linuxrenderer: drop method RenderMultiPass
linuxrenderer: implement progressive weave for vdpau
VDPAU: silence compiler warnings
vdpau: release more resources on pre-cleanup