Topicfixing merge and updates

Invisible because this branch was so far behind develop, but the following changes are included:
* Locally cache json files while in debug mode, so that as you're re-running script to debug, you don't have to download all over again.
* Remove any unrecognized exercises, since we can't deal with them (only 14 at the moment)
* Make sure to blow away the old topicdata, then recreate, as some of them become cruft.
* Some other random things that I don't remember.

Note:
* This will become the base branch for the path/paths change in NODE_CACHE that will solve some of the tricky caching issues.