Ensuring that a serie can be added to multiple organisational units
Clean-up in orgunit, series and events:

 - Make validation messages a bit more consistent
 - Cleaned up orgunit dao jsdoc
 - Added EventsAuthz.canCreate and cleaned up authz jsdoc
 - Cleaned up calendar serialization and added CalendarInfo model
Added foreign key columns to each DB model and cleaned up jsdoc a bit
Fixed failing groups paging test on Ubuntu
Using lodash’s utility functions rather than typeof
Validator tests

- Cleaned up isMediumString and isLoggedinUser
- Added test for isGlobalAdmin
Events cleanup

 * Created a DAO.getOrganisers
 * Asserting optional event properties
 * Expanded authz tests
Groups cleanup
Lower-casing users their displayname to avoid weird sorting errors
Parallelised user creation in the tests
Added dropOnStartup to the config
Removed unimplemented addOrgUnitEvents call
Removed sourceId references
Organisational units cleanup

* Authz: The orgunit’s group members can update, delete and add/delete series to/from it
* Expanded integration tests
* Consistify validation
* Make JSDoc consistent with REST docs
Cleaned up gh-rest

* Added encodeURIComponent to all URL parameters
* JSDoc fixes
Series - cleanup

* Cleaned up JSDoc
* Cleaned up validation
* Added canCreate authz check
* Expanded integration tests
Merge branch 'groups-events-series' of https://github.com/fronteerio/grasshopper into groups-events-series
Added a script that allows you to import an organisational unit structure completed with series and events
Re-use the group once a module is being created when importing the tree