Merge pull request #3378 from FernetMenta/aefixes

ActiveAE: make sure sink list is not empty when settings query the default
vdpau: exit gfx lock in OnLostDevice and OnResetDevice
vdpau: increase timeout for display event, some systems are too slow switching refresh rate
vdpau: drop old ffmpeg vdpau_render_state
vdpau: clear processed pics on flush
vdpau: reactivate long decoding time debug message
vdpau: keep video surfaces for another cycle
vdpau: create only a single vdpau device
vdpau: make sure buffers a full before returning a picture
vdpau: move common attributes into vdpau context
vdpau: drop pixmap magic, it violates the spec
vdpau: reduce number of render pics
vdpau: cosmetics
vdpau: fix incorrect spcifier in settings for vdpau mixer
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
renderer: bump buffers to 5
videoplayer: update frametime, it might change due to fps detection
videoplayer: give streams with invalid fps a chance for fps detection