pkgin package repository message (Was: 9.0 is getting old...)

[David Brownlee <abs%absd.org@localhost>]

It occurs to me that it would be helpful to provide a way for a binary
package repository to inject some form of message into pkgin users.

This could be used to tell 9.0 and 9.1 users that they need to upgrade
to >= 9.2, or that a repository has stopped being updated and they
need to switch somewhere else, or some critical issue in pkgin

It could be as simple as a text file in the package dir, automatically
checked and downloaded by pkgin, combined with logic to display it
always (bonus points for having pkgin commane line option to stop
showing the message until it changes)

What do people think?

David