Update linux+mac bluetooth state files when using custom pairing

Currently psmove_pair_custom appears to be kind of useless (correct me if I'm wrong) on linux, because when using it the host side of the pairing operation does not take place.  This rectifies that, and therefore makes scenarios like pairing controllers to different dongles on the same machine a possibility.

Also changing btaddr_string and btaddr to the more descriptive new_host_string and new_host.