Instead of registering a handler to run when the database is created,
register a variable and check it immediately to run the schema import.
This avoids a problem where an error between database creation and
schema import 1) leaves the server in a broken state, and 2) rerunning
the playbook doesn't fix it.

Clean up some artifacts from the merge to match the `jessie` branch.
Keep the changes on master made with commits bfe6fe84 and e229c551.

An earlier commit started transitioning opendmarc to use postgres, but
this was incomplete.  This patch reverts that change and uses mysql for
the reporting database.

Other changes:

* Do not maintain a copy of the database import schema.  A copy is
  included in the distribution in /usr/share/doc, so that is used
  instead.
* The configuration file is replaced with the distribution's sample
  configuration.  A second patch will restore the actual configuration.
  This will make the changes easier to see if the default configuraton
  file changes in future versions of opendmarc.

Resolves #400.

Resolves #410.

 * fix mail_db_opendmarc_username/mail_db_opendmarc_password variable
   not found.
 * python-mysqldb package is required. Add it to opendmarc task.