remove 2 training missions as suggested in
issue #868
don't keep around those right-side fort files which are just mirror images of left-side forts. generate them at run-time instead. note: inlining changes and deleting files - so consider clean build/install
just ignore gfDivideTeams if more/less than 2 teams. instead of quitting with fatal error
chat: make sure that CTRL is the /only/ modifier key pressed when detecting ctrl+a etc