convert to oauth2 ids

- add epochs
- delete epochs
- delete collections

closes #3, addresses cni/nimsweb#16, cni/nimsweb#17

closes #2

- refine what is logged to logging levels

- internimsclient separated from nimsapi.wsgi
- args and config have more consistent naming
- using api_url instead of hostname
- improve internims error handling
- bootstrap.py ensures remotes collection index