BATCHEE-24 add a sample persistence.xml to our zip
we don't need the apache snapshots repo anymore
BATCHEE-24 exclude unlisted entities
add maven-release-plugin and tweak it for GIT
rename batchee-parent to just batchee

* this will contain the source.zip in the maven repo
* will also give a nicer tag name by default
rename batchee-parent to just 'batchee'

whoops missed to also fix the child projects