Refactored some code for Moose integration.

There now exist a DM::Job and DM::JobArray class that are used by DM.
The DM::Job class is used for parsing and storing basic rule information.
The DM::JobArray class is used for job arrays.  Both DM::JobArray still
needs to have its interface revised.  Potentially, some code from DM
could be moved over to it, or another class...