Merge tag '1flow-0.28.1' into develop

0.28.1 1flow-0.28.1
Fix http://dev.1flow.net/1flow/1flow/group/30194/
version bump for 0.28.1.1.
Merge tag '1flow-0.28.1.1' into develop

0.28.1.1 1flow-0.28.1.1
Merge branch 'release/0.28.1.1'
Bring back the admin links.
Try to make the admin part of user subscription visible again. NOT SURE, it should be working already.
Update the CONTRIBUTING.md for new i18n way of doing things.
Avoid another crash when trying to extract article title, and use the new i18n procedure.
Small update with real examples in CONTRIBUTING.md
More CONTRIBUTING i18n documentation and examples.
Rework the title extraction conditions, try to make things easier to understand.
version bump for 0.28.1.2.
Merge tag '1flow-0.28.1.2' into develop

0.28.1.2 1flow-0.28.1.2
Merge branch 'release/0.28.1.2'
HEADS UP message for tasks names.
Fix #22 and avoid a crash at the same place if working with a feed link in non-english language.
Get back the old code, this was not the problem (see next commit).
Create a new `has_staff_access` property and document the difference with the pre-existing `is_staff_or_superuser_and_enabled`.
Use the new `has_staff_access` property where appropriate. Better messages when staff tries to access stuff in staff mode and privacy option is enabled.