* Have ScriptModule inherit from Module
This is accomplished by created replacement _parameters, _buffers,
and _modules which implement the OrderedDict APIs but which
actually get/set their members inside script::Module
* Merge TracedModule with ScriptModule
* Move logic of attribute handling into Python bindings rather than
make script::Module handle it. This was redundant with nn.Module,
which already handles attribute.
* Make TracedModule a subclass of ScriptModule
* Move handling of attribute kind logic into bindings.
* Allow ScriptModule to contain non-script module submodules.
