dynamic light speedup, patch from Eric Wasylishen, based on an earlier work by MH.

git-svn-id: svn://svn.code.sf.net/p/quakespasm/code/trunk@933 af15c1b1-3010-417e-b628-4374ebc0bcbd
restore compilation with g++, some whitespace tidy-up.

git-svn-id: svn://svn.code.sf.net/p/quakespasm/code/trunk@934 af15c1b1-3010-417e-b628-4374ebc0bcbd