xt branch: having a float version of gr_opengl_string makes text scrolling nice and smooth at high nonstandard resolutions
(also, looks like quad rendering works just fine here; no need to convert to tris)

convert credits.cpp to use float version of gr_opengl_string; eventually Taylor wanted to make the float version standard

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11127 387891d4-d844-0410-90c0-e4c51a9137d3
xt branch: add capability for custom identifiers in build names (e.g. Xt-0314)

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11128 387891d4-d844-0410-90c0-e4c51a9137d3
xt branch: optimizations in modelcollide.cpp

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11129 387891d4-d844-0410-90c0-e4c51a9137d3
xt branch: minor tweaks to glow_points

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11130 387891d4-d844-0410-90c0-e4c51a9137d3
xt branch: use CLAMP here

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11131 387891d4-d844-0410-90c0-e4c51a9137d3
according to the C standard...
"The functions snprintf() and vsnprintf() write at most size bytes (including the trailing null byte ('\0')) to str."
...so we have that going for us, which is nice

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11132 387891d4-d844-0410-90c0-e4c51a9137d3