Allow users can create and management their groups.

I added a feature that members can manage their group. If you are turned OFF by default, this feature is not the same as ever. When the administrator to change the settings from the System Settings, user can use this function.

- The user can create a group from the account page of their own.
- Automatically, member list of the group has been created, it contains the author of the group.
- Members will be able to edit the profile of the group to which they belong, to manage the member list.
- The user will not be able to leaves a group themselves.
- The user can not be deleted group.