Merge pull request #4414 from Memphiz/ios7airplayfix

[airplay] - fix regression introduced by ios7 clients
Merge pull request #4335 from Jalle19/change-default-level

Use FF_LEVEL_UNKNOWN by default (prevents some common mismatches in
Merge pull request #4337 from voguemaster/only_allow_extend_duration_real_streams

Do not allow non-content stream types to extend the format context's dur...
Merge pull request #4433 from FernetMenta/alsa

AE: add verbose logging, start with alsa logger
Merge pull request #4436 from ace20022/ext_sub_details

 [Ext. subs] Use ISO639-2 T language codes for external subtitles details.
Merge pull request #4457 from fritsch/pa-gotham-fixes

ActiveAE: Fixes for gotham
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
xrandr: observe orientation