Cleanup gnewweap.c and add sanity checks
Cleanup g_phys.c and add sanity checks
Cleanup src/g_spawn.c and add sanity checks
Cleanup g_sphere.c and add sanity checks
Cleanup g_svcmds.c and add sanity checks
Cleanup g_target.c and add sanity checks
Cleanup g_trigger.c and add sanity checks
Cleanup g_turret.c and add sanity checks
Cleanup g_utils.c and add sanity checks
Cleanup g_weapon.c and add sanity checks
Cleanup client.c and add sanity checks
Cleanup hud.c and add sanity checks
Cleanup trail.c and add sanity checks
Cleanup view.c and add sanity checks
Cleanup weapon.c and add sanity checks
Cleanup ball.c and add sanity checks
Cleanup tag.c and add sanity checks
Add file headers

With this commit the game logic is cleaned up. Coop spawnpoint cleanup
is still missing, it'll be done at a later time. While not completely
finshed, rogue should alread run much more stable than the unmodified
code. Please note, that this is still untested! Headers are next,
monsters will be done after that.