[horde] automatic failover mode

[liam hoekenga]

Has anyone put any thought into an automatic DB failover mode?  Such that.. if
you were set to use a SQL backed prefs system, and it couldn't connect to the
database, rather than throwing a fatal error, it would revert back to a prefs
backend of "none" or "session", and throw up a note that said something like
"The preferences database is unavailable.  You're using default preferences for
the duration of this session"?

Liam