always draw border on terrain if there is only a map mask and no map image. this is a workaround for the fact that space campaign masks use white (lfObject) color instead of black (lfBasic)
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