changed: Auto extract thumbs/flags for webdav
GUIEpgGridContainer: validate scroll offsets as well as they are used to calculate rendered blocks
GUIEpgGridContainer: don't select first item on mouse/touch event on empty programme block
GUIEpgGridContainer: don't react on clicking channel list
GUIEpgGridContainer: add panning gesture
GUIControlGroupList: add panning gesture
Add media parameter to Playlist.Item directory type

Allow complete control from remote of the media to add, now permit a correct Player.Open on directories with mixed items.
Also permit to have metadata loaded when files are added from Player.Open
Forcing a wrong type for a specific playlist return an invalid params.
Now also authorize to queue videos to pictures playlists
[Python] Adds autoclose to python's yesno dialog.
[ffmpeg] fix: patch needs to operate from lib/ffmpeg
Add python-imaging dependency its been a ppa dep since 2011

Add zlib1g-dev Readme.ubuntu since has been part of ppa deps for a while too
and its part of readme.linux.

Full A-Z Alphabetical sort on both readmes's as per wsnipex comments

Squash all into 1
[release] version bump to 13.0 alpha4 as we start new merge window.
Fix undefined reference caused by wrong detection of gcc builtin atomic functions.
fixed: DVDPlayer GUI display time not updating near the end of file (fixes #14299)
[dvdplayer] fixes PGS subtitles
Merge pull request #2666 from FlyingRat/fix-PGS-subtitles

[dvdplayer] fixes PGS subtitles
Merge pull request #2674 from arnova/dvdplayer_displaytime_fix

fixed: DVDPlayer GUI display time not updating near the end of file (fix...
Merge pull request #2664 from MartijnKaijser/may_window

[release] version bump to 13.0 alpha4 as we start new merge window.
Merge pull request #2587 from pieh/panning

Add gesture handling to GUIControlGroupList and GUIEpgGridContainer
Merge pull request #2560 from arnova/auto_stuff_for_webdav

Allow auto extraction of thumbs/flags for webdav sources
Merge pull request #2567 from Tolriq/media_playlistitem

Add media parameter to Playlist.Item directory type