Extending the item manager to handle items

[connorclockwise]

The itemManager class currently reads in weapon information. There should be a range of powerups throughout the game and one way to encapsulate said abstractions is through items. The itemManager should read in an items.xml file and parse it for items, then create item class prototypes that can be instantiated throughout the game. If you need a reference for the first part, look in the actorManager initActorConfig method.

[mitjmcc]

I'll try this out.