Added meta-information about hopper classes as a module-level dict.
Minor PEP8 correction.
Consolidated CLASS_IDS and CLASS_PARAMS dicts into one.

I added the CLASS_IDS info to CLASS_PARAMS and then generated
CLASS_IDS automatically from CLASS_PARAMS.  Cleaner and better.
Merge branch 'hoppers_meta_info' into django_initialization_and_early_stages