linux: switch to linux-3.13 per default (except RPi)

Signed-off-by: Stephan Raue <stephan@openelec.tv>
scons: convert to new package format, move package

Signed-off-by: Stephan Raue <stephan@openelec.tv>
swig: convert to new package format, move package

Signed-off-by: Stephan Raue <stephan@openelec.tv>
nasm: convert to new package format, move package

Signed-off-by: Stephan Raue <stephan@openelec.tv>
yasm: convert to new package format, move package

Signed-off-by: Stephan Raue <stephan@openelec.tv>
libdrm: update to libdrm-2.4.51

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