navigator mavlink log info messages: add #audio tag
fw autoland: remove confusing slopelength parameter
fw autoland: completely remove the virtual wp between the last wp and the landing wp. autoland starts now from the last normal wp.
fw autoland: fix warning
fw autoland: remove old comments
fw autoland: add very short comment
navigator: remove all but one [navigator] tag from mavlink audio messages
Merge pull request #664 from thomasgubler/beta_audio

navigator mavlink log info messages: add #audio tag
Merge pull request #682 from thomasgubler/beta_fwautoland

Beta: fw autoland remove virtual waypoint
Disable time compensation which gets us reasonable results
Merge branch 'beta' of github.com:PX4/Firmware into paul_estimator