No major changes, but I prefer to stay close to upstream, for obvious reasons.

Patch by NightStrike

This also gets rid of one user of setjmp(), but it is still found in
the (stupid?) PNG codec and OS X interfaces.

...and VLC does not quite work on Linux 2.2 anymore.

As it doesn't seem to be called after creating playlist in core on startup
and playlist-model calls rebuild on creation anyway.

Also remove item-current from playlist-model which ain't used.

for future generations

This allow a little bit more flexibility and won't require the same level of code quality in configure tests (is that a plus?).