Case Sensative User Modifications

chlib.ConnectionManager.user: No longer converted by .lower()
chlib.Group.user: No longer converted by .lower()
chlib.Group.usrl: New Variable with .lower version of chlib.Group.user
chlib.Digest.unblocked: Now compares group.name with group.usrl
chlib.Digest.logoutok: Modifies group.usrl at the same time as group.user