don't mount the mod folders at all for make docs

fixes #3873
one / too much in the end
brought back the MoveFlash

closes #2592
StyleCop cleanup
removed unused Iron Curtain palette
separate TargetFlash from DrawLineToTarget
only use Self for internal self references
avoid additional layers of abstraction
don't stack flashes and filter non unit actor related orders
Merge pull request #4049 from Mailaender/make-docs-fix

Fixed make docs for downstream packagers
correct the bindir for Debian launcher scripts

fixes #4048
Merge pull request #4050 from Mailaender/usr-games-deb

Fixed broken start scripts for DEB packages
loop all orders only once
StyleCop cleanup
don't ignore bools
nudge the grounded pilots after ejections
added trait documentation
update changelog
Merge pull request #3999 from Mailaender/moveflash

Brought back the MoveFlash
Merge pull request #4045 from Mailaender/pilot-nudge

Cleanup EjectOnDeath and nudge pilots