[fix bug 860339] Update group url matching regex.
[fix bug 866662] Calculate group unique url based on aliases.
[fix bug 860339] Randomize avatar filenames.
[fix bug 866677] Allow /csp/report through StrongHold Middleware.
[fix bug 704081] Add attribution to use of Tumbeasts
Merge pull request #463 from Falkulator/attribution

[fix bug 704081] Add attribution to use of Tumbeasts
[fix bug 859945] Task to delete empty groups.
Merge pull request #462 from glogiotatidis/866677

[fix bug 866677] Allow /csp/report through StrongHold Middleware.
Merge pull request #461 from glogiotatidis/849712

[fix bug 860339] Randomize avatar filenames.
Merge pull request #459 from glogiotatidis/859945

[fix bug 859945] Task to delete empty groups.
Merge pull request #460 from glogiotatidis/860339

Stuff for groups
[Fix Bug 867791] rename some userprofile to members
[Bug 866041] change gravatar url to https
Merge pull request #465 from Sancus/giorgosforgetstorenamethings

[Fix Bug 867791] rename some userprofile to members
Merge pull request #466 from Sancus/makegravatarhttps

[Bug 866041] change gravatar url to https