Selective explosion of sub-assemblies about cq-annotate HOT 1 OPEN

Both the short and long term options should be possible. The explode_assembly method does not currently use CadQuery's traverse method for assemblies because that method did not yet exist when I established this project. explode_assembly needs to be refactored to use that, which will handle arbitrarily deeply nested assemblies and will allow filtering by name, assuming that an assembly name is set (it is not required and CadQuery will use a generated UUID if it is not set).

It should also be easy to accommodate the recursive argument, but I should probably refactor the code for traverse first since that will change how the recursive argument is handled.

from cq-annotate.