Merge branch 'develop' into import_data

Completely reworked data import stuff. Added a new package
called `data_import` with a command line interface in
import_data.py.

Please check README.md for new instructions on how to
download and import data.
Merge branch 'import_data' into develop
Merge branch 'import_data' into develop
Add some docs that were accidentally removed
Add the first 'motioner' docs