Merge pull request #3 from quaker66/master

enet cflags checking
upstream imports
fix LLVM warnings
remove some remaining yaw+90 stuff
add q66 to the OTHER credits too
sync theme with Leo's from sandbox
fix build
remove stray comma
fix loopfiles duplicate detection, also allow some more math operators to have >= 2 arguments
minor loopfiles optimisation
s/r_spawn_creature/r_spawn_critter/ to reflect the entity type
fix newentity inserting garbage