Don't allow modifying qvms or pk3s

Exception for allowing pk3s to be downloaded.
Rename FS_CheckFilenameIsNotExecutable to ..NotImmutable
Rename FS_CheckFilenameIsNotImmutable to ..IsMutable
improved location damage a little bit (work still needs to be done on it)
Remove fallback r_picmap

Should have been r_picmip, but don't want that set to 1 unless user specifies it.
Merge remote-tracking branch 'ioquake3/master'

Conflicts:
	code/qcommon/files.c
Don't reset r_texture* to non-default values

These where the Q3 defaults, but doesn't really make sense to set them after crashing.
Correct TeamCount return type and team argument type
Merge remote-tracking branch 'ioquake3/master'
removed ammo boxes
all weapons are registered on startup
players start out holding their primary weapons
made weapon types to determine what the weapon fires (bullets, rockets, shotgun shells, sniper rounds, etc.)
a major goal is to reduced/remove code that checks for a specific weapon so removing/adding weapons into the game is easier and less spread out in the code
#5889: Do post-processing only on viewport portion of frame buffer.
Merge remote-tracking branch 'ioquake3/master'
made a universal rocket/launcher firing function (fire_missile), bullet_fire will eventually be merged into this and then probably g_missile.c and g_weapon.c will be merged
made bulet_fire use new g_weaponinfo in g_weapon.c (same as bg_weapons but with different information that is only used for server)
merged g_missile.c into g_weapon.c (left prox launcher stuff in g_missile.c for later though)
renamed Missile functions to Projectile functions
merged gmissile_t into g_weapon_t
made bullet_fire use fire_missile
renamed fire_missile -> fire_projectile
moved spread code into fire_projectile and removed the need for bullet_fire
Merge branch 'master' of git://github.com/zturtleman/spearmint