in order to be consistent with other libvlc methods (libvlc_media_player_get_length, get_time, ...)

(cherry picked from commit 35baa96f7b3493737c1575c2dbffc7946a9c04df)
Signed-off-by: Jean-Paul Saman <jean-paul.saman@m2x.nl>

If vlc_cancel() while the timer thread is between mwait() and
vlc_mutex_lock(), a dead lock would occur at vlc_join(). We need to
release the timer lock first.

Invoking
python vlc.py filename.avi
will play the given movie.

It would be nice if its syntax was the same as all other enums...

Pointed-out-by: Taylor Venable

(and also remove an unneeded include).

At the moment it doesn't handle those size/bold/* stuff, only takes font
from it. But IMO still better than old file-choosing way.

Parameter is default, so no need to tell it here.

according to doc, thisway view should be able to do some optimisation
over itself, and I didn't figure out anycase that rows wouldn't be same
height on playlist.

Previously, the core would fallback to other demux plugins which was
inefficient and error-prone.

A plugin can use this if it matched but detected a non-recoverable error
while inside the open callback. Help yourself if you want a "better"
error code.

exit() cannot return negative numbers (the high-order bits are ignored).
And anyway, that's not a meanigful place for VLC error codes. It is also
questionable whether we should exit() from LibVLC anyway...