update CONTRIBUTING.md
Merge pull request #3671 from stefansaraev/contributing

update CONTRIBUTING.md
libmad: build static

TODO: not used in core. move to unofficial?
Mesa: update to Mesa-10.3.5

Signed-off-by: Stephan Raue <stephan@openelec.tv>
kodi: update to kodi-14-8d4cdb5

Signed-off-by: Stephan Raue <stephan@openelec.tv>
misc-firmware: update to misc-firmware-0.0.13

Signed-off-by: Stephan Raue <stephan@openelec.tv>
wlan-firmware: update to wlan-firmware-0.0.26

Signed-off-by: Stephan Raue <stephan@openelec.tv>
dvb-firmware: update to dvb-firmware-0.0.47

Signed-off-by: Stephan Raue <stephan@openelec.tv>
linux: update to linux-3.17.5

Signed-off-by: Stephan Raue <stephan@openelec.tv>
xf86-video-intel: Downgrade to version 910

ref #3597

no need to keep 916 in master. lets be in sync with 5.0