admin interface for db auth store

[smoku]

creates a second executable, usermaint, from the c2s objects. this executable can add and delete users and update passwords. it should work for any writeable auth store, but was written to all administration of berkeley db auth stores.

probably needs some work around logging (since it's basically impersonating the c2s server w/r/t logs).

bundled into a tar archive since I could only attach one file.

[smoku]

Patch by Brian H. Ward <brian.ward@…>