Added support for external configuration.

injection_complete now expects SEL instead of NSString.

Added support for mapping blocks.

GIInjector#removeModuleClass will remove all Modules of the given class.

Adds Child Injector.

Changed GIInectionMapper api.

Specify custom selector, when injection is complete.

Inherits required properties from parent.

Changed GIInjectionMapper api.

Properly unloads modules when resetting injector.