Make UI for Group Management.
Add used strings in strings.xml.
Make the ManageGroupActivity and add it to the Manifest. Also add list related classes.
Modify Friend Profile Activity so the friend can be added to a group from there.
Modify Add Friend Activity so the friend group can be set when adding.
Modify Friend Request Fragment so in case of an accept the friend can be placed in a group.
Modify Database + Constants + Friend for group management purposes.
Add logic for group management in Main Activity.
Solve conflicts.
Merge branch 'Corly-master'