Add version facts

Breaking up the elements of #48 into smaller bitesize pieces :+1: 

This gives new facts `::java_version` and `::java_patch_level`

This means, even before there's a solid fix for #48, you can easily add some logic in your manifests to only update Java when versions out of date.

This will also fix https://github.com/boxen/puppet-java/issues/49, by adding some logic around checking if on OSX 10.10 and failing if release too old.