Besides other issues, this should fix an integer overflow breaking IPv6 address
aquisition after a runtime of 50 days.

This also removes our mac80211 backport for now, as the version found in
Attitude Adjustment is up-to-date.

This *should* fix the build on non-Linux systems like MacOS X.

This should fix the TX power problems with the TL-WR841N/ND v9.

Only compile tested, might not work.

This allows us to drop our config mode patch.

This updates OpenWRT and rebases our patches.

Furthermore, the mac80211 module is removed as currently the Attitude Adjustment
main repo has a newer version (and some fixes that aren't in the backport repo).

Also, update odhcp6c from Barrier Breaker.