Added a bunch of new app icons

Apps I've added so far:
 * Amazon Kindle
 * Battle.net
 * Colloquy
 * Curse Client
 * IntelliJ
 * MAMP
 * Page Layers
 * Sequel Pro / MySQL
 * Serato DJ
 * Twitter

Apps I am currently working on:
 * 1Password
 * EasyGet
 * Flowdock
 * Things
 * World of Warcraft

Also working on drive and folder icons. Feel free to let me know if you don't like any and I will remove.