Rewrite code for switching to next slide.
Slideshow rewrite the error handling code.
Change CGUIWindowSlideShow::Select() to use same condition with code
loading first picture in Process().
Change AnnouncePlayerPlay to announce speed == 0 for pausing slideshow or picture.
Keep slide infos during video playback.
Unify picture display effect during slideshow or pausing, browsing.
Add big play button for video in slideshow/picture window.
Set direction to forward when starting a slideshow by action.
Allow change slideshow direction.
rename IsDisplayEffectNeedChange to DisplayEffectNeedChange.
Slideshow reduce race condition when background loading picture.
Remove whole reload picture on zoom code, since we do not really use it.
[musicdb] fix: db updates fail due to duplicate keys creating unique indexes for musicbrainz
[rbp] Remove unnecessary gl ifdef

I'm not sure why this was originally added.
I couldn't think of a reason why the Pi would want things done differently here,
so I tried without the ifdef. I can't see any difference in behaviour,
so I think we're better off removing it.
[language] update locations where string IDs are used ofter settings refactor
[musicdb] fix the curlfile crash on exit properly this time
add Player.IsInternetStream Infolabel
[depends] - add libshairplay
[win32] - bump libshairplay to the same version we use in unified deps
[depends] - remove libshairport as its superseeded by libshairplay now