Collective.contact.plonegroup

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- Fixed typo in french translation.
[gbastien]

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- Added parameter `omitted_suffixes=[]` to `utils.get_all_suffixes`.
[gbastien]

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- Avoid useless variable initialization in `utils.get_plone_group`,
do everything in one line.
[gbastien]

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- Warning, changed behavior of `utils.get_organization`, added parameter
`only_in_own_org=True` that will make sure that given `org_uid` is an
organization inside own organization.
[gbastien ]
- Added `get_selected_org_suffix_principal_ids` and `voc_selected_org_suffix_userids`
to work only with group and user ids
[sgeulette]
- Used cached method `get_users_in_plone_groups` from imio.helpers
[sgeulette]

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- Added `utils.get_suffixed_groups`.
[sgeulette]
- Do not delete a group (after a function removal) if not empty
[sgeulette]

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- Escape user and group title in `DisplayGroupUsersView`.
Moreover fixed column to be not sortable.
[gbastien]
- Added `safe_utils.py` that will only include safe utils.
[gbastien]
- Corrected error in search: do not pass empty portal_type criteria.
[sgeulette]
- Added parameter escaped=True in `voc_selected_org_suffix_users` function
[sgeulette]
- Fixed `display-group-users` when organization is not selected in plonegroup
so there is no linked Plone groups, added tests for it and the
`suborganizations` view (z3ctable displaying organizations contained in
another organization).
[gbastien]