Dereferencing now respects max_depth, so should be more performant.
Reload is chainable and can be passed a max_depth for dereferencing
Added an Observer for ComplexBaseFields.
Refs #324#323#289Closes#320
No change required to upgrade to multiple databases. Aliases are used
to describe the database and these can be manually registered or fall
through to a default alias using connect.
Made get_connection and get_db first class members of the connection class.
Old style _get_connection and _get_db still supported.
Refs: #84#87#93#215
