Set a Maven Property indicating if a database reused or created.

This feature can be useful to control the behaviour of subsequent Maven steps. For example, if a database is filled with default data, a user might want to skip this step if an existing database was reused. See “example-database-reuse.apt.vm” for an example.
no need to use `String.format` here, `Logger.info()` does exactly the same, see: http://log.jcabi.com/apidocs-0.14.1/com/jcabi/log/Logger.html