----------------
- Made compliant with Plone 4.3, 5.2 and 6.0
[sgeulette]
- Ordered imports & improved docstring
[sgeulette]
- Factorized increment/decrement functionnality in `settings.increment_nb_for`,
`settings.decrement_nb_for` and `settings.decrement_if_last_nb` functions.
Added helper function `settings.set_settings`.
[gbastien]
- Fixed `ConnectionStateError` while setting `registry[TYPE_CONFIG]`
in tests and profile is applied several times.
[gbastien]