Allow specification of a parent POM

The roo-generated pom is extremely verbose. While it makes for a solid build, it is somewhat difficult to read.

As a compromise, it would be nice if you could specify a parent artefact when you run 'create project...'. If this parent contains <pluginManagement /> and <dependencyManagement /> sections, then there would no need to explicitly specify versions for all the plugins and dependencies in the project's pom, leading to a smaller pom.

You could use standard g:a:v notation, something like 'create project -parent org.example:superpom:1 ...' to make the association.