councils keys should not be included when testing permissions for a group

castles respond to holders. users respond to holder_codes. The two are very different. holder_codes has all the codes for holders the user has access to. castle#holders are all the holders that have access to a given castle. We should not include the latter when a castle is used like a user (testing permissions it has on other castles or itself). Otherwise it will inherit permissions from holders with access to itself.
fixed Groups::PermissionsController#update to be able to grant rights to the group.
Also removed BUG notice from Groups::PermissionsHelper#members_may_edit_wiki_checkbox.

Conflicts:

	app/helpers/groups/permissions_helper.rb