In ricochet-qt, contacts were stored with a sequential numeric ID, and
that was used in various places to refer to the contact uniquely. The
habit carried over here in an attempt to keep configuration
compatibility.
These IDs are error prone (particularly over RPC) and unnecessary. This
removes the entire concept and uses addresses to index and refer
uniquely to contacts everywhere.
The default address will be set from the environment, or fall back to
trying 127.0.0.1:9051. There is now an API to allow this to be
overriden as well.
John Brooks