#17 Uniform object string system

[Mark Curtis]

All objects that are known to the engine will have certain properties that are useful to access via a string 'name'. Some example uses for such a system would be:
- Access nodes in the scene graph by name
- Allowing scripts access to object properties (such as material properties, node transforms etc)
- Allowing animation instances to retrieve references to their channel targets

Such a system should be flexible enough to allow retrieval of objects of a number of different types (not just nodes). Also, the querying of the system should have multiple entry points (not just a single engine function). This will allow relative addressing within the node tree (eg: anim targets relative to passed 'base node').