Collision: insert a really stupid workaround: make every trace 1qu longer, and retroa...

Collision: insert a really stupid workaround: make every trace 1qu longer, and retroactively shrink the trace when done.

Bug this works around for: when doing a trace from A to B, B being just slightly inside solid, the trace ends "successfully" with fraction 1. However, a trace starting in B will be startsolid. This workaround removes this inconsistency, which sometimes causes map fallthrough, and should have no other side effects, not even a noticable performance impact.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@9085 d7cf8633-e32d-0410-b094-e92efae38249