Alter YAML export to use yaml_db plugin

[dnrce]

Migrated from the original issue at https://www.assembla.com/spaces/tracks-tickets/tickets/736

Alter the YAML export button so that it uses yaml_db. This produces a nicely formatted data.yml file which contains both schema and data for all the tables. This can be used to load the data into another installation via the command line, or to migrate from one database adapter to another. In future, we might be able to hook up import via the web UI, so that data could be imported the same way, but that requires a bit of cleverness with users.

Originally reported by bsag on June 6, 2008 at 05:36:45 (-0400)

[dnrce]

yaml_db is unmaintained, but a more general ticket for this issue is #1702.