VoutReworkOrganization

Roadmap

For more on the concepts (not very formalized) please see VoutRework

* Make a SVN branch (0.8.5-vout)
* Make the vout singleton that manages windows and inputs
  * Create the singleton
  * Create the notion of vout_window, vout_region, vout_input
* Add the new type of buffers (video + black bands for subpictures, at output resolution)
  * Modify the processing chain for this
* Make the Great Unified Crop/Pad/AR thing
  * Core part
  * Modular part (standard C, or using OS capabilities)
* Rework SPU Unit 
  * Allow "absolute timing" (OSD) or "stream timing" (subs)
  * Ability to work at video resolution (DVD Subs) or output resolution (OSD, text subs)
* Rename video_filter2 to picture_filter
* Add ability to add picture_filters in the chain