MVP debugging tools

- readme
- debugging options to mvp report indicator apis
- minor cleanup
- import / export indicators from one domain / instance of HQ to another as json file
not 100% sure i understand what's going on, but if `override` is `True` it looks like this will just keep dumping indicators to the DB (but i'm guessing none but the most recently modified are ever touched). is that intended? would it make sense to delete the old ones?