[fix bug 969098] Mark announcement text safe.

- Also added 'u' in allowed tags.
[Fix bug 969063][Fix bug 968988] Fix group membership admin for unvouched members

autocomplete_light was raising validation errors because its
autocomplete field for members on the groupmembership model
was limited to vouched members but some groups have unvouched
members.

Modified the admin for group memberships to use an autocomplete
field that accepts any user profile.
Merge pull request #804 from caktus/969063-968988-admin-unvouched-members

[Fix bug 969063][Fix bug 968988] Fix group membership admin for unvouche...
[Fix bug 969663] Added id to submit and create group buttons to fix 969663
Merge pull request #805 from glogiotatidis/969098

[fix bug 969098] Mark announcement text safe.
[fix bug 969598] Show only functional areas on empty search results.
Merge pull request #801 from jpotts/fix_969663

Added id to submit and create group buttons to fix 969663
[Fix bug 968340] Correct plurals in curator email
Merge branch '968340-curator-email-pluralization'
[fix bug 969531] Change Functional areas to accept new members.
Merge pull request #806 from glogiotatidis/969598

[fix bug 969598] Show only functional areas on empty search results.
[fix bug 962223] Add subheader for admin settings on Edit Group view.
[fix bug 898064] Add 'update' button on top
Merge pull request #807 from glogiotatidis/969531

[fix bug 969531] Change Functional areas to accept new members.
Merge pull request #809 from glogiotatidis/962223

[fix bug 962223] Add subheader for admin settings on Edit Group view.