add option for instant alien health

yo, this is kmg

This adds an option called "Instant Alien Health Bar" which turns off all animation on the alien health ball (health and armor). I haven't worked with NS2Plus or done any NS2 modding before really, so hopefully I got the conventions somewhere close to correct. Let me know if there are any changes I could make so that it fits better.

This is just something that has bugged me for a while, when I take a shell as a fade I want to know how low I am as soon as possible :P

There may of course be issues with this I overlooked, I'm just a lowly noob, but I'd be very appreciative of a merge.