Merge pull request #4451 from fritsch/pa-volume-fix-mainline

PulseAudio: Rework Volume
Merge pull request #4481 from mus65/wiiupro

[Linux] add basic support for Wii U Pro Controller
Merge pull request #4467 from Memphiz/osxnosamplerate

[osxsink] - for devices which report samplerate 0hz - allow user overrid...
[lang] update of internal addon language files
[lang] update of core language files
[lang] update of skin.confluence language files
version bump to 13.0 beta4
videoplayer: adapt lateness detection and dropping to buffering
video player: present correct pts to user for a/v sync (after buffering in renderer)
videoplayer: some rework and documentation
renderer: bump buffers to 5
videoplayer: update frametime, it might change due to fps detection
videoplayer: give streams with invalid fps a chance for fps detection
dvdplayer: allow rewinding at end of stream, do a seek after rewind
X11: ditch SDL for video and window events
X11: Add xbmc icon
X11: add SDL joystick until we have a better solution
X11: factor out code handling device reset notification
X11: move xrandr events to WinEventsX11
xrandr: remove method RestoreState