[keyboardlayout] Add Greek QWERTY

Greek QWERTY keyboard layout. All accented characters are under "symbol,shift+symbol". No space for the capital accented characters though.
Merge pull request #5967 from host505/patch-2

[keyboardlayout] Add Greek QWERTY
Revert to software decoding for AVC profile 578 as it is not handled by imx6 VPU
EGL: Add Quirk for display recreation
IMX: Announce EGL_QUIRK_RECREATE_DISPLAY_ON_CREATE_WINDOW to fix refreshrate change
Merge pull request #5966 from fritsch/imx-helix-ports
vdpau: advanced settings for auto deinterlacing
ActiveAE: slightly reduce buffer size
pthreads: use mutex protocol PTHREAD_PRIO_INHERIT
vaapi: lock gfx context on pre-cleanup
Bump xbmc-pvr-addons ref