xbmc-pvr-addons: MySQL support should not be magically detected

thanks to: Georgi Georgiev <chutz@gg3.net>

closes #2381
vdr-addon: fix utf-8 in vdr.start

before (bad)
Jun 15 19:54:32 openelec user.err vdr: [2298] codeset is 'ANSI_X3.4-1968' - unknown

now
Jun 15 20:04:38 openelec user.err vdr: [2608] codeset is 'UTF-8' - known

closes #2380
linux: update to linux-3.9.6

Signed-off-by: Stephan Raue <stephan@openelec.tv>
ffmpeg: enable gnutls support

Signed-off-by: Stephan Raue <stephan@openelec.tv>
xbmc (Gotham): update to xbmc-57f529b, update XVBA/VDPAU patch

Signed-off-by: Stephan Raue <stephan@openelec.tv>
vdr-addon: bump
projects/RPi: update RPi kernel patch

Signed-off-by: Stephan Raue <stephan@openelec.tv>
Merge branch 'master' of github.com:OpenELEC/OpenELEC.tv