c[Fix bug 939815] Implement add/edit/delete portal base content

* Activities
* Campaigns
* FunctionalAreas
Merge pull request #605 from glogiotatidis/939815

[Fix bug 939815] Implement add/edit/delete portal base content
[fix bug 965726] Do not list inactive activites or campaigns.
[fix bug 965743] Do not list special activities.
Update test docstrings.
Merge pull request #606 from glogiotatidis/965726

Activities listing
[bug 956775] List continuous reports
[bug 956775] Add list report tests.
[fix bug 956775] More detailed list tests.
Merge pull request #609 from glogiotatidis/cr-601-dev

NGreports list
Removed campaign and event from NGReportFactory.

Both 'campaign' and 'event' are not required fields of an NGReport and
should not be populated automatically or unexpected things may
happen. For example creating an NGReport using the factory, would in
fact create two reports, the second of which was triggered from the
event created by the Event subfactory.

Similarity campaigns should not be auto-populated, since we expect
campaign field to be not null when activity is set to the special
'Participated in a campaign' string and not just a random Activity.
[bug 956775] Fix error in list_ng_reports tests_views.
Merge pull request #610 from akatsoulas/fix-list-reports-tests

[bug 956775] Fix error in list_ng_reports tests_views.
[fix bug 945831] Task to send digest of report activity to mentors.
[fix bug 966987] Display mentor in reports.
Merge pull request #614 from glogiotatidis/966987

[fix bug 966987] Display mentor in reports.
Merge pull request #612 from glogiotatidis/945831

[fix bug 945831] Task to send digest of report activity to mentors.
Make sure there's defined event in report before using it.
[bug 932853] Display continuous reports in dashboard
[fix bug 967506] Clean up comment form on successful save.