ffmpeg: update to ffmpeg-1.2.4, move patches

Signed-off-by: Stephan Raue <stephan@openelec.tv>
samba: update to samba-3.6.22

Signed-off-by: Stephan Raue <stephan@openelec.tv>
scripts/unpack: rework content of stampfiles

Signed-off-by: Stephan Raue <stephan@openelec.tv>
scripts/clean: rework cleaning of sourcepackages in a more intelligent way, cleanup and cosmetics

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