Great work 
Just to note I installed the ‘latest’ osx version from the osx links on this page:
http://ardupilot.org/planner2/index.html
And seem to have ended up with 2.0.18.
There’s an issue when we migrated to the new ardupilot.org site and the new 2.0.20 build didn’t get copied over.
[ADDED LATER[
It’s fixed for OSX, i’ll do win and linux in the morning (PDT)
http://firmware.ardupilot.org/Tools/APMPlanner/apm_planner_2.0.20_osx.dmg