* Initialize SDL before opening the SDL audio output.
* Prevent two SDL video outputs or audio outputs to be spawned at the
same time to avoid ugly crashes.
* The SDL plugin now says whether we are using software or hardware YUV
in its window title.
* We now stop at the first ':' when looking for a module name, to easily
pass information to the modules. Possible example: --vout sdl:software,
implementation of such an option is left as an exercise.
* Merged filter_bob and filter_bob422 into filter_bob. Use --filter bob
to deinterlace 422 into 420 as well.
* Factorized code common to most filters and the video output, optimized
a few filters by aligning data and reading 64 bits at a time.
* Two new absolutely useless, CPU-eating, resource-wasting, but fun
filters: enjoy `transform', which performs flips and 90� rotations, and
`distort', which performs animated image effects (currently only a naive
sine wave is implemented). Usage examples:
--filter transform:hflip
--filter transform:vflip
--filter transform:90
--filter transform:180
--filter transform:270
--filter distort:wave