fix for each Object loaded with so many properties

[yankscally]

With collisions layers etc. There are at least 64 properties per object, this is terrible for optimisation.

The solution:
make a "subscribable" property that can be loaded at runtime on each object.
according to Valy I can do property loading outside of the init.py, which means dynamic properties are novel to support

so essentially - something like this:
bpy.types.Object.body_properties = bpy.props.PointerProperty(type=bless.OMIPhysicsBody)
can be called when the panel is changed in any way. the problem is that the panel can't load them in draw(), so I will have to use my imagination.