Create a new admin binary.

[jholdstock]

The vspd binary is intended to be a non-interactive long-lived daemon which serves the VSP website and handles the lifecycle of added tickets. However, it currently includes some one-off admin tasks which are necessarily interactive, e.g. initializing the database.

The impact of not having a proper home for this kind of admin task can be observed in #311. Interactive password changing is obviously a nice feature to have, but fitting it nicely into the vspd daemon is awkward.

A dedicated binary for performing admin tasks without the concern of remaining non-interactive would provide an obvious ideal location for this kind of function. It could potentially even mean that tasks such as changing the admin password can be performed without having to stop/start the vspd process, another obvious win.