config/version: change version back to 'devel'

Signed-off-by: Stephan Raue <stephan@openelec.tv>
gcc: update to gcc-4.9.1

Signed-off-by: Stephan Raue <stephan@openelec.tv>
ffmpeg: update to ffmpeg-2.3

Signed-off-by: Stephan Raue <stephan@openelec.tv>