[UX] consistent playback behavior for music and video
[pvr] use channel path instead of channel name for CFileItem path property
[pvr] sync selected item between pvr windows
[markwatched] queue up mark watched jobs and process them without locking the main thread
[markwatched] handle mark watched via mark watched job queue
[X11] Add support for EGL/GLESv2 when using X11
Merge pull request #5113 from Phaeodaria/egl-x11-pr

[X11] Add support for EGL/GLESv2 when using X11
Merge pull request #5199 from xhaggi/pvr-select-current-playing-item

[pvr] sync selected item between pvr windows
Merge pull request #4923 from mkortstiege/markwatched

handle mark watched via job queue
dvdplayer: remove log spam after 7ab52a00ac516ecb784f86a190fd44c523359cf7
[darwin] Add model detection for OS X
[pvr] cosmetics: renames m_selectedItemPath to m_selectedItemPaths to reflect it's a map
[pvr] fix selecting current playing item

As m_selectedItemPaths is a map we need to check if the corresponding map value is empty instead of the whole map.
Merge pull request #5317 from Karlson2k/osx_model_id_01

[darwin] Add model detection for OS X
Merge pull request #5325 from xhaggi/pvr-fix-selecting-playing-item

[pvr] fix selecting playing item in PVR windows
Merge pull request #5245 from da-anda/consistent-playback

[UX] consistent playback behavior for music and video
Add setting to hide library clean progress bar.

This adds {music,video}library.backgroundclean, similar to backgroundupdate.
Hides the progress bar for library cleans.
json-rpc: explicitly pass showProgress in VideoLibrary.Clean.

This allows it to respect videolibrary.backgroundclean.
This way one can remotely clean the library and it won't prompt the user for
unavailable sources.
See:
https://github.com/xbmc/xbmc/blob/master/xbmc/video/VideoDatabase.cpp#L8035-L8037
https://github.com/xbmc/xbmc/blob/master/xbmc/video/VideoDatabase.cpp#L8310-L8312