skeleton for a lunar lander lesson
get rid of .fr.html files and modify po4a.conf instead
revert it.po
remove scala and python entities for now
add lessons.lander to ExoTest (breaks it)
outline of the upcoming series of exercises in Main.html
add almost empty LanderWorld
rename LanderWorld to the name of the class that is the actual world as seen by PLM
Merge pull request #135 from polux/lander_skeleton

skeleton for a lunar lander lesson