Fancy colorful server alerts.

So...I made an enhancement for the server alert system. It adds support for alternate colors (green and red besides the default purple). Although minor, this is something we've been looking to add to Survival for Reasons™.

* /alert add <message> is now /alert <color> <message>
* (Supported colors are purple, green and red)
* Short aliases: /alert-p, /alert-r, /alert-g
* Handles existing alerts that do not have an associated color

![screen shot 2014-05-29 at 5 14 13 pm](https://cloud.githubusercontent.com/assets/158727/3123792/456a855a-e776-11e3-8d96-f5196ef81c11.png)

This shouldn't affect anything for the other servers if they don't wish to use non-purple alerts (aside from having a shorter /alert-p <msg> command available), and it's all been thoroughly tested.