Support for behavioral discrepancies in vanilla linedef types under Heretic, special thanks to Gez for pointing most of these out.

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2376 86ba831e-150c-0410-ab35-e06eaae15ed9
osx: Renamed owner with mOwner in some instances

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2377 86ba831e-150c-0410-ab35-e06eaae15ed9