Emergency O2 tanks shouldn't be pure O2

[mbc]

If you use it correctly, an emergency O2 tank will pretty much last you an entire round, and you never even need to worry about it. This makes the more cumbersome air mix tank that you wear on your back almost completely useless.

I think both tanks should be filled with an air mix, so you actually have to save your emergency O2 tank as a temporary measure for emergencies (or fill them up with O2 from a canister).

Also, spawning with internals should be randomized again. Right now you are guaranteed an emergency tank when you spawn.