[BUGS]
* Fixed missing permissions
* Fixed owner leave group and cannot assign to another.
* Fixed invite form still show even visitor did not have permission to see.
* Fixed cannot create group in some cases
* Fixed not clean up member alerts when member leave group.
* Fixed cannot upload new cover in some cases.
* Fixed album counter make 2 lines.
* Fixed member counter wrong in some cases.
[FEATURES]
* Added option to show group members in widget (apply for style full only)
* Added alert to member when they be promoted.
* Added alert to member when be assigned to group admin.
* Added alert to user when they be assigned to group owner.
* Added new permission `Bypass view group privacy` which allow users browsing any groups.