Improve spectrum visualization. Change options : the number of bands for the spectrum and spectrometer visualization is now set with a boolean. Ban some actions to avoid segfaults in visualizations.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Pointed-By: Eric Lassauge

The original idea and debug come from basos g patch with the following
comment:

"A dead lock was created when adding an spu filter (like marq)
because the same mutex was used for spu->p stuff and sub filter
chain (p_spu->p->p_chain)."

 I implemented the creation/destruction of the chain outside the sub-filter
callback.

Added a comment to describe inheritable variables
Added debug messages to get clues about variable
inheritance final source
Signed-off-by: Laurent Aimar <fenrir@videolan.org>

Signed-off-by: Laurent Aimar <fenrir@videolan.org>

Also partially (internally only) fix missing Win64 drawable bits

If multiple video ouputs exist, only one will now use the drawable.
This still does not implement drawable size, window type and probably
Win64 support properly.

Also, this is not currently used by libvlc_media_player_set_drawable
although it probably should. This function looks pretty weirdly -to
stay polite- implemented.

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

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

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

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

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

Modifications by /me (renaming, var_Get, hotkeys, etc..)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

The leading :sout=  appears to confuse the destination parser which causes the sout to be prepended with an empty access and mux resulting in an invalid output chain.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Still a lot of testing and fixing needed.
The profiles are still in the main Qt Settings file.

It adds possibility to store IDs for Anchors, Panels and Groups.
This does not change the way skins2 works I believe. It just stops the
XML parser from complaining about non standard skins when they have set
IDs for those elements. And setting IDs for them is vital in the skin
editor, as it differentiates between different elements in the skin just
by their ID.