auto-importer doesn't support modules not imported by their parent

[Andrew Wilkins]

You have a package "a", and a module within called "b", i.e.:-
    a/__init__.py
    a/b.py
a/__init__.py does NOT import b.py.

The auto-importer currently is a bit dumb, assuming that the parent imports the child. Based on this assumption, a auto-import of "a.b" works as follows:
    getattr(getattr(conn.modules, "a"), "b")

This will fail if a doesn't import b.

[Andrew Wilkins (axwalk)]

It is possible to get around this at the moment, by doing this:
    getattr(conn.modules, "a.b").b
The second getattr is necessary since __import__ is used.

I can think of a couple of options for fixing this:
    - Modify ModuleType proxies to do an import on getattr, if getattr otherwise fails.
    - Add an explicit import function to pushy.Client which handles sub-modules.

I am currently thinking of doing both. If feasible, the first option should only apply to modules returned from the auto-importer.