Adds abilities outlined in #623, adds server description to the database, the server screen and also notifications, it doesn't add it to the main status screen.

It's all based off of the older version as I started it in August, so sorry about that :P

I've updated the install script, however I haven't added provisions for updating the database on a version upgrade, the following MySQL will need to be implemented. I added the description as a VARCHAR(500) in case people wanted to add an extra long description, or even other configurations or notes in there:

ALTER TABLE `[PSM_DB_PREFIX]_servers` ADD `description` VARCHAR(500) NOT NULL DEFAULT '' AFTER `label`;