[release] version bump to 13.0 alpha2 as we start new merge window.
Add compilationartist property to AudioLibrary.GetArtists
Remove unused variable initialization
[rbp] Fix for audiotoggledigital on Pi.

Pi only has two audio output modes so the three way toggle gets stuck. This fix corresponds to Pi specific settings code:
https://github.com/xbmc/xbmc/blob/master/xbmc/settings/GUISettings.cpp#L458
CGUIDialogVideoInfo: show all existing artwork types for a specific media type in the "Choose art" dialog
Merge pull request #2194 from Montellese/chooseart_all_artwork

show all existing artwork types for a specific media type in the "Choose art" dialog
Add support for limits to Files.GetDirectory

Also removes an unneeded loop.
Merge pull request #2366 from Tolriq/AddLimitsToFilesGetDirectory

jsonrpc: add support for limits to Files.GetDirectory
Merge pull request #2248 from Tolriq/compilationartist

jsonrpc: add compilationartist property to AudioLibrary.GetArtists
Merge pull request #2252 from popcornmix/toggle_digital_analogue

[rbp] Fix for audiotoggledigital on Pi
[rbp] Enable Vsync as a default
[cec] use client version 'current' now that libCEC 2.1.0 is being used. also fixes 'when the tv goes to standby' option being reset, since libCEC now checks the version correctly for that option
[cec] prevent duplicate power on commands from being sent
Merge pull request #2243 from MartijnKaijser/13.0alpha2_bump

[release] version bump to 13.0 alpha2 as we start new merge window.
Merge pull request #2388 from popcornmix/enable_vsync

[rbp] Enable Vsync as a default