Fixes issue for me when doing transcode{}:gather: --sout-keep and subtitle
overlaying from dvbs. Otherwise keeps last subtitles on video if new channel
doesn't contain dvbs track.

also consistenty as spu_Create is called on transcode_spu_new()

Changing places of items depending on their actual usefulness
Removing one tab
Reordering tabs according to usefulness
Reordering of tab order and buddies

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

This needs heavy testing and improvement to be actually usable

Removal of UDPport... This doesn't belong here

Otherwise, VLC sometimes selects the impaired track instead of the
usual/default one. This is a major annoyance with YLE, the Finnish
national broadcaster. YLE routinely provides a visual impaired audio
track in Finnish (declared as Dutch for some reason!) in addition to
the original version.

Modifying from the configuration won't work anyway (since VLC overrides it).

Close #3040

Close #4177

Adding posterize filter to Color fun tab of Video effects tab of Effects
and filters dialog
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Only update image and notify for those mouse events that we care about.
This removes the job being done twice (once on mouse pressed and once
 on mouse released)