* Add pull command.
* Add publish command.
* Enforce start's old semantics.
* Add pull test cases:
- Pull with no events anywhere
- Pull with one event on mobilizon and none on the db
- Pull with one event on mobilizon and another on the db
- Pull with one event on mobilizon and the same event on the db
* Add pull tests:
- Sequence: pull->start
- Sequence: start->pull
- Sequence: pull->new event on mobilizon -> pull
* manifest.scm: Add cloc.
* query: read: Prefer return list to generators.
* tests: pull: Actually test that models are written to the DB.