Seiscat

- CSV output for `seiscat print`, using `--format=csv` (or `-f csv`)
- Special argument `ALL` for `seiscat editdb` to edit all the events
(or all the events of a given version when used together with the
`--version` argument)
- New option for `seiscat editdb`: `--increment` to increment (or decrement)
a numeric field by a given, positive or negative, amount

- New command to edit the event database: `seiscat editdb`
- `eventid` argument for `seiscat print`, to print a specific event
- Fix bug where an event was updated when extra fields were set to a different
value than the default
- Fix bug where an event was updated to new version even if the same event
already existed in the database

- New configuration option: `overwrite_updated_events`. Default is `False`
and updated events get an incremented version number
- `--allversions` option for `seiscat print` and `seiscat plot` to print/show
all the versions for events with more than one version
- `--format` option for `seiscat print`: current possibilities are `table`
(default) and `stats`
- `--reverse` option for `seiscat print`: if set, latest events will be printed
on top
- Rename database column `dep` to `depth`

- Command line autocompletion, thanks to argcomplete
- Show event depth in plot annotation
- `--scale` option for `seiscat plot`
- Correctly parse evids from USGS and ISC
- Exit gracefully if database file is missing
- Fix printing of `None` values

- New command to print catalog to screen: `seiscat print`
- Documentation!

- Fix for plotting the whole world when no limits are given
- New way of computing zoom level for map tiles