DBSettings: log the uri we're connecting to

Change-Id: I0f83f2c499bc0ffffb3ff1bf5ae77fb7362cd142
Use __name__ as logger name

This defaults to foo.bar.baz and avoids a bit of duplication
when specifying the logger.

We're leaving stoqlib.{database,import}.create loggers, as they
have a special meaning in the user interface.

Change-Id: I463a2679daac49a2b03b0422d4af9ef7b13f1e51
Merge "DBSettings: log the uri we're connecting to"
Merge "Use __name__ as logger name"