Clean up config format, errors, make vars global

* Pretty-printed the JSON for the config file
* improved error handling to cover all of the main script
* made the variables that will be logged for each run global because of
  namespace shenanigans
Refactor and add documentation to mbapi

* Started working on API continuations; not done yet and untested but a start
* Added docstrings to complete methods in mbapi
* Updated matchbot for compatibility with refactored methods in mbapi
* Separated list creation and API call in the categorymembers methods

Barring further refactoring, it's likely that the structure of this is
pretty close to final form.