Personal information about commiter shall be managed by profiles

* there should be a method to manage commiter alias
    * Work: "myname <email address hidden>"
    * Spare Time "myname <email address hidden>"

    Sometimes, users mistakenly use the wrong name alias.
    There should be something like:

    $: bzr commit
    bzr: want to commit as "myname <email address hidden>"?

    This could also be done via commiter profiles.

Also configuration such as connections.conf could relate to these.