Add a link for viewing user's permissions after changing them

The use case:

1. I look at a user's permissions.
2. I decide to change the permissions by following a link to change permissions from view permissions page (http://tracker.phpbb.com/browse/PHPBB3-10130)
3. Now I want to verify that permissions are correct by viewing them again.

There should be a link from the edit permissions page back to view permissions, similarly to how there is a link from viewing permissions to editing permissions.

Note: after permissions are changed, the "go back" link takes me back to user search. The "back" link should probably return to editing permissions. See http://tracker.phpbb.com/browse/PHPBB3-10131.