Restructuring the node graph related directories.

Node graph related directories have been moved into the NodeGraph directory.
The follows moves were perform.
- the nodegraph dir has moved to nodegraph/entities
- the drawablenodegraph dir has moved to nodegraph/drawables
- the hub dir has moved to nodegraph/hubs
- the compositeshapes dir has moved to nodegraph/shapes

The shared libraries will also now have NodeGraph_ prepended to them.
The rest of the changes in this commit deal with modifying the includes
to include from the right location.