Ensure that the decoder is init once only.

This fixes the crash while playing MPEG2 files with sequence display extension.
allow <width>auto</width> for label controls, and ensure dirty-regions works with them. Part of #13887
Handle keystrokes in the web interface remote (up, down, left, right, play/pause, ...)
Speed up ffmpeg format probing if we'll trust codec fps.
Handle letters and digits keystrokes in the web interface remote
LinuxRendererGL: trigger reset of scaling when entering/leaving fullscreen video
VideoRenderer: add gui setting for threshold when hq scaling is desired
[python] Notify python code about double clicks
Merge pull request #2023 from jmarshallnz/allow_zero_auto_width_labels

allow <width>auto</width> for label controls
Merge pull request #2454 from FernetMenta/scale

LinuxRenderer: avoid double pass rendering if no scaling is done
Merge pull request #2447 from aglebov/on-double-click

[python] Notify python code about double clicks
Merge pull request #2379 from juanfont/fpsdetect

Speed up ffmpeg format probing if we'll trust codec fps for playback
Merge pull request #1954 from anuj-m/master

[vaapi] Fix crash while playing mpeg2 files
Merge pull request #2033 from PhenX/master

Handle keystrokes in the web interface remote (up, down, left, right,…
fixed: stupid c&p mistake
changed: degrade logging to from INFO to DEBUG

thanks to nemphys