Implementation of ParameterTree that Matches the Underlying C++ Structure.

[ajgdls]

1. The Python adapter controller performs a regular request for status and configuration from underlying applications.
2. For each reply, the structural update timestamp (formerly hash) will be checked.
3. If this is different to the previous timestamp (should always be the same or newer), then trigger a metadata request and completely rebuild the ParameterTree.
4. The controller can contain a cache member variable that the incoming status/config is assigned to.
5. When the ParameterTree is rebuilt, the RW attribute will need to be checked. If R, then pass in a getter. If RW, then pass in a setter and getter.
6. The getter should be wrapped using a partial, supplying the path to the leaf node. This can be used within the getter to index into the cached member.
7. The setter (if required) can also be wrapped in a partial, and the path can be used to build the correct form of IpcMessage to send to the underlying C++ applications.
8. When a structural change occurs, throw away the ParameterTree and completely rebuild a new one with the new structure.