Only allow vt_int cvars with a range of 0 to 255 to be used as the source for lockdef automap colors.

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2666 86ba831e-150c-0410-ab35-e06eaae15ed9
Line type 99 should not have a lockdef ID binding in Heretic.

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2667 86ba831e-150c-0410-ab35-e06eaae15ed9