- replace TextAreaField by StringField for several Text columns
- add filter to replace empty string by None on optional Text and INET
  fields

Don't override the Admin view __init__ method for consistency.
Avoid having to import models in admin/views.py

CIText is displayed as a TextAreaField by flask-admin.
Override it to use StringField.

- Allow to pass several mandatory fields in create_generic_model
- Add tests

- A network defines an available range of IP addresses
- A host defines an IP address and name
- A host is always linked to a network
- A mac address is always linked to an item (physical equipment)
- A mac address can be linked to one host (IP)
- An item can have several mac addresses

Text is as efficient in Postgres and is recommended over varchar.
It avoids having to put an arbitrary max length to strings.

CSE makes it clearer that it's linked to CSEntry

Add button to return to main index

ics_id, serial_number, manufacturer_id and model_id should not change.
Repeating them in the history table takes space for nothing.

We are only interested in tracking the status, location and parent.

- catch IntegrityError on patch
- disable autoflush (IntegrityError was raised before commit due to
autoflush)

Pass ?qrcode=true as query string

Can use:

  -  /api/items?serial_number=123456
  -  /api/items?location_id=1

This allows a client to login only once a day.

We might want to decrease that and look into refresh token.
But this looks overkill for our use case.

- add more tests
- patching an item update children location and status
- setting the parent on an item updates the location and status with the
  parent ones

This can be done via the Admin interface but this latter shall be
restricted to admin users. This simple page allows the group "create"
to easily add new Manufacturer, Model or Location.

To make it easier, different decorators are created
depending if the user logged in using a JWT (API)
or cookie (web UI).

Clean code at te same time.
The macro from flask-bootstrap already takes care of everything.

- update flask-bootstrap
- update datatables to v1.10.15 for bootstrap 4 support

The CIText type is not known by Flask-Admin and was not rendered.
A custom model converter is required.

See https://github.com/flask-admin/flask-admin/issues/1196