Adding light and camera components and other smaller changes
+ Light component
+ Camera component
= Component constructors have changed to allow components to use parent gameobject in their constructor
+ Some comments to clarify requirements for component derivers, in terms of ctor/dtor
+ Camera manager which has a set of the live cameras and keeps track of which is active
+ Added bindings necessary to cleanup the scene
= Change how lua EventDispatcher works so callbacks can be registered without a context
+ Added invalid handle (-1) and assert macro for handles
= Split light manager handles to different
+ Update methods for lights in light manager
= Camera move/rotate code has moved from rendermanager to updatemanager (will eventually end up in script)
- Render manager no longer owns the camera