[pvr] fix unnecessary creation of new CPVRChannel instances
[builtin] fix activatewindow if directory path differs

After #5081 the built-in "activatewindow" does not work if you stay for example in the video window and you want to activate the same window with a different path.
This fixes the issue by comparing the directory path of the current active window with the given directory path of activatewindow.
[ios] - support iphone6plus screensize which uses screenScale 3 and add
support for iPhone6 screen aswell
[ios] - add launch images for ip6 and ip6+ for enabling the new resolutions
[ios/vtb] - remove the video render scale down / clamp for all retina devices which have enought power to render unscaled
[ios] - add support for iPad Air 2 and iPad mini 3
[pvr] fix call to base class GetContextButtons() to re-add favorite entry
vaapi: workaround intel bugs
Merge pull request #5473 from AlwinEsch/pvrfix-guiinfomanager

[pvr] fix unnecessary creation of new CPVRChannel instances
[pvr] fix continue playback of last watched channel on startup if group was deleted or channel was moved
[omxplayer] Restore flush/accurate seek flags to fix issue with edl skipping
[PiSink] Dual audio support

The Pi supports dual audio in omxplayer, where the gpu outputs audio to
both hdmi and analogue connections.

With dvdplayer being more usable on Pi now, there are frequent requests
for this functionality through the Pi Sink.

This removes the gui setting for "dual audio" and creates a new sink
output for dual audio. It add support to the Pi sink and makes omxplayer
use the new setting.
Merge pull request #5526 from xhaggi/pvr-fix-continue-last-channel

[pvr] fix continue playback of last watched channel on startup if group was deleted or channel was moved
Merge pull request #5547 from xhaggi/pvr-fix-context-menu

[pvr] fix call to base class GetContextButtons() to re-add favorite entry
Merge pull request #5490 from xhaggi/fix-built-in-activatewindow

[builtin] fix activatewindow if directory path differs
Merge pull request #5390 from Memphiz/iphone6

[ios] - support iphone6plus screensize which uses screenScale 3
Merge pull request #5554 from popcornmix/edl_flush

[omxplayer] Restore flush/accurate seek flags to fix issue with edl skip
Merge pull request #5557 from popcornmix/pisink_audio

[PiSink] Dual audio support
vaapi: glIsSync, glIsTexture seem to unreliable on Intel
[ios] - fix devcert signing (pvr addons were missing and couldn't be loaded)