xt branch: optimize objectsort.cpp by not calculating some things every loop iteration

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11133 387891d4-d844-0410-90c0-e4c51a9137d3
fix a compile error (d'oh) and use type safety

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11134 387891d4-d844-0410-90c0-e4c51a9137d3
wut?  defaulting to NULL here will cause these to never log anything...

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11135 387891d4-d844-0410-90c0-e4c51a9137d3
string printing safety

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11136 387891d4-d844-0410-90c0-e4c51a9137d3
SCP_string is useful here too

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11137 387891d4-d844-0410-90c0-e4c51a9137d3
xt branch: more string safety

git-svn-id: svn://svn.icculus.org/fs2open/trunk@11138 387891d4-d844-0410-90c0-e4c51a9137d3