[fix bug 748559] Change group url to /group/<url>.
[fix bug 832968] Make group.url unique with AutoSlugField.
[fix bug 763513] Redirect GroupAliases to parent Group if exists.
[Fix Bug 698912] Add Apple Touch icons for all iOS devices
Merge pull request #383 from Sancus/iosicons

[Fix Bug 698912] Add Apple Touch icons for all iOS devices
Merge pull request #378 from glogiotatidis/groups

Groups