changed TraceBox functions to take start,mins,maxs,end like they did in Quake, this...

changed TraceBox functions to take start,mins,maxs,end like they did in Quake, this is a slight optimization to traceline and pointcontents tests and q1bsp tracing, but mostly just cleans up the code
removed some old code from q3bsp TraceLine/TraceBox functions
changed segmentmins/maxs and nodesegmentmins/maxs calculations to have a 1 unit enlargement on all comparisons, this might improve reliability of TraceBox, but probably not

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@6085 d7cf8633-e32d-0410-b094-e92efae38249