BOMs refactoring

Please DON'T MERGE THIS YET. It is still work in progress, but I want to get early feedback from others, so that's why I am creating this PR.

We discussed some of the changes with @ge0ffrey @rafabene and @pmuir in past few weeks. With @ge0ffrey  we decided _not_ to move the BOMs to community repositories as they should only be released when product is actually released. We will still create a CI job that will locally build the BOMs and quickstarts and will sure they work as expected.

The following changes should be done as part of the refactor:
* introducing `brms-bmpsuite-bom-parent` that will contain the shared info like version properties, etc
* added `jboss-brms-bpmsuite-bom` that contains only the drools/jbpm/optaplanner artifacts (no javaee stuff)
* refactored the `jboss-javaee-6.0-with-drools` into `jboss-javaee-6.0-with-brms-bpmsuite` as it already listed more than just Drools artifacts.


I couldn't resolve this version. Since this BOM is 6.1.0-SNAPSHOT, shouldn't it be using the same version for KIE ?