changes: add some things for completeness
vdpau: don't try to match codec profiles

Instead, do what MPlayer did all these years. It worked for them, so
there's probably no reason to change this.

Apparently fixes playback with some files, where the VDPAU decoder does
not formally support a profile, but decoding works with a more powerful
profile anyway.

Though note that MPlayer did this because it couldn't do it in a better
way (no decoder reported profiles available when creating the VDPAU
decoder), so it's not entirely clear whether this is a good idea. An
alterbative implementation might try to map the profiles exactly, and
do some fall backs if the exact profile is not available. But this
hack-solution works too.
vaapi: use highest available profile, instead of mapping it exactly

Now the code does the same as the original MPlayer VAAPI patch, instead
of trying to map the profiles exactly.

See previous commit for justification and discussion.
mplayer: reshuffle on every loop if --loop and --shuffle are used

See github issue #194.

Unfortunately, this breaks the property that going back in the playlist
always works as expected. This changes, because the playlist_prev
command will work on the reshuffled playlist, instead of loading the
previously played files in order. If this ever becomes an issue, I
might revert this commit.