dvdplayer: factor out render config flag from OutputPicture
dvdplayer: cosmetic alignment of checks
renderer: split out frame move from render action in video renderers
renderer: move waiting for next frame into rendermanager
core: drop Update() from IPlayer and paused state from renderer

We never called it on players and we never asked renderer to pause
renderer: fix race condition in FlipPage
move NUM_BUFFERS up to BaseRenderer.h
dvdplayer: add interface to codec for number of shared references

This is how many references to pictures that can be retained when
calling Decode the next time around
renderer: replace BYTE* with uint8_t*
linuxrenderer: delete all textures on reconfigure
renderer: calculate present parameters before setting up fields

We don't even need to hold lock here potentially
renderer: add buffering to render system

This allow renderer to queue up frames for display after decode.

Original Implementation By: Rainer Hochecker <fernetmenta@online.de>
renderer: allow dropping at output stage when we have a replacment frame

Allo dropping a frame that is about to be rendered, if it is late
and there already exist a replacement frame that should be presented
now.
renderer: skip second field of bob deinterlace if late
add buffering - some documentation
dvdplayer: display pictures skipped on output
(dvd/omx)player: drop now redundant code for frame drops on output

RenderManager can now take care of this in a much more intellegent
fashion
renderer: take separate lock instead of exclusive lock for present queue

This looks rather messy. But is solves an important performance issue
where decode thread would be blocked waiting flip by render thread while
it was rendering current frame.

Without this faster than display rate decode is not possible
renderer: reduce thread ping ponging by using real condition variable
renderer: fix hang if we DiscardBuffers and try to start again