Qt: now that you don't control the controls size anymore, be careful to resize the controller when buttons show up.

Close #2487.

(see http://forum.videolan.org/viewtopic.php?f=2&t=56224&p=186350)

Those were never used from plugins. This commit is a no-brainer.

This could crash the input thread(s).

This allows invoking debuggers directly from the command line again!

This allows using the http interface directly when builddir != srcdir.
This is needed to get rid of the ./vlc script.

According to ffmpeg/libavcodec/mpeg12enc.c:155 (rev:2fd06be07311)
profile and level must be inited at the same time, so, -1 will be
returned for mp2v with width > 720 or height > 576. But, if we leave
this fields blank (i.e. FF_PROFILE_UNKNOWN and FF_LEVEL_UNKNOWN) avcodec
will init them correctly.

This partially reverts commit b1b72b63.
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

This fixes the previous behaviour that was confusing.

Close partly #2237

Qt: cohenrency for volume between FSC and main Controller. Solve the 1% issue reported by Trax, close #1851.

We need to fix that better in post 1.0.0
Close #2377

Qt: remove the HACK with the static QAction for minimalViewAction, and fix a few minimalVIew issues.

 * add the possibility to go slower and faster (wasn't finished)
 * some cleaning and factorization