[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.
Respect parent path decision when cleaning paths.

When cleaning the video library and a source containing TV shows was unavailable,
choosing to keep it only kept the source root, while subdirectories were
removed.
The result was that TV shows "disappeared".

This is fixed by checking if there's a decision for the parent path when
cleaning the path table.
DVDInputStreamTV/DVDInputStreamFile: Don't set EOF in case of error to give player a chance to retry read.
[vfs] PVRFile::Read(): do not return negative values other than "-1"
[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
[ios] - bump gas-preprocessor
[ios] - support Xcode 6.x and iOS 8 SDK

- use clang as default compiler for newer SDKs
- fakeroot: ignore interposing openat()
[ios] - fix libssh build with Xcode 6
[ios] - fix pil build with Xcode 6
[ios] - libRTV fix build for Xcode 6
ios] - fix libmpeg2 build error by making it even more PIC (also the real fix for the xcode5 build issue earlier)
[ios/atv2] - adapt readme - we support Xcode 6.0.1 against iOS 8 SDK
dxva: fix memory leak caused by additional ref on video surfaces
[smb] only log if samba logging is enabled
[pvr] bump add-ons
[pvr] fix call to base class GetContextButtons() to re-add favorite entry