Update OpenWrt

This now includes the previously added patch.
mac80211: add another ath9k patch
Update Gluon packages
docs: update autoupdater documentation
Update Gluon packages
ar71xx: disable building u-boot for ZyXEL devices

The u-boot package has some issues causing its build to fail under certain
circumstances. As we don't support the ZyXEL devices it's used for anyways, just
don't build it anymore.
docs: autoupdater: fix example build script
Update netifd and odhcp6c from Barrier Breaker
Update netifd from Barrier Breaker
Reduce fw3 log spam in netifd scripts
Update Gluon packages
Link to hackint.org added
Merge pull request #146 from DerDerwish/master

Link to hackint.org added
allow GLUON_SITEDIR to be set by environement
docs: fix builds.rst
scripts: fix GLUON_SITE_CONFIG

check_site.sh and site.sh were setting GLUON_SITE_CONFIG on their own
even though the environment variable was already exported.
Update netifd from Barrier Breaker (r41888)