Namespacing and config

Namespaces the xooie AMD modules and adds config support.

Config values can be set multiple ways:

// Before loading xooie:
Xooie = { /* config values */ };

// After loading xooie:
Xooie.config({ /* config values */ });

Currently supports the following configs:
modules - Map of module name to AMD module to load
addons - Map of addon name to AMD module to load