the need for compilation fixes with standard headers.

Clean up vcdx a bit. Or a lot. It compiles, but I can't test. Since apparently nobody uses this anyway it shouldn't be a big problem.

Refactor vcdx info.c dropping a few memory leaks and other problems. It compiles, but I can't test it.

Nibs will be added later on. No user-visible change as of yet.

I guess nobody ever tried to use that piece of code.

N.B.: dose not apply to bugfix due to earlier non-backported bugfixes

Also, show the popup menu on press rather than release.

On Linux, these functions cannot fail. On Windows, mutexes cannot fail
and neither can real condition varaibles (but we use events instead to
support pre-Vista versions). In practice, the needed resources are
allocated as part of the mutex structure and per-thread data.

In any case, basically none of the call sites for those functions were
checking for errors. It seems best to abort in case of error than to
hit undefined behaviour. We probably do not want to clutter the tree
with untested never used error paths.

Those two functions can actually fail and leave the handle undefined.
vlc_join() and vlc_thread_join() would then crash (say, be undefined),
so errors should be taken care of explicitly.

Also remove conflict between browser back/forward and mouse wheel.

Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

Doesn't work because variables callback can't be removed from their own callbacks.
Some work will be required here.