[Fix Bug 962191] Migrate groups without a curator to accept new members
[Bug 938005] Fix timezone helper tests
Fix bug 963295 - Fix group merging
[fix bug 961060] Add certificate icon next to group name if user is curator.
[Fix Bug 951513] Curator alignment

Squashed commits:
restored curator detail layout placement.
removed unnecessary nesting
removed unnecessary margins from curated group info box contents.
Merge pull request #787 from Sancus/fixtmzutilstests

[Bug 938005] Fix timezone helper tests
Merge pull request #786 from Sancus/legacygroups

[Fix Bug 962191] Migrate groups without a curator to accept new members
Merge pull request #775 from caktus/963295-fix-group-merging

Fix bug 963295 - group merging
Merge pull request #780 from glogiotatidis/961060

[fix bug 961060] Add certificate icon next to group name if user is cura...
Merge pull request #779 from caktus/951513-group-info-alignment

951513 group info alignment
[Fix Bug 949080] write a south data migration to revalidate all twitter usernames in the db