Mail notifications for administrative actions

Right, let's specify what will be required:

 * An administrative mailing list for distribution, let's say "<distro>-changes-admin"

 * Overrides changes: We will have a ISSPPH/ISBPPH.reason field and change-override tool will send an email to the admin ML containing a report of the executed action.

 * Package Removal: The same ISSPPH/ISBPPH.reason field will be used, remove-package tool will send email as change-override.

* New Package acceptance: queue tool already send email to the <distro>-changes maillisting, should we Bcc the admin ML as well ?

* Build admin actions: it will be part of the build-failure-notification spec, but I'm not sure we should collapse the messages in the admin ML, buildd-failures are supposed to have their own ML.

Apart of small details, we can do this quickly before edgy release, Maybe we should right a small/straightforward specification for this.

Promoting it to *High*, since we expect good reflects for the distro team.

An additional action which should send notifications, as described in bug #48895, is the arrival of a package in an UNAPPROVED queue. This should notify the archive administrators so that they can take action in a timely fashion.