OOPath documentation

We have an experimental feature called OOPath in BRMS engine. If we want to move this feature to supported features set, we must create documentation for it.

We have some upstream docs about this feature here:
https://docs.jboss.org/drools/release/6.5.0.Final/drools-docs/html/ch10.html#d0e13581
(The same in upstream Asciidoc: http://docs.jboss.org/drools/release/7.0.0.CR3/drools-docs/html_single/#_browsing_graphs_of_objects_with_oopath_2)

There is a paper written about it here:
https://www.researchgate.net/publication/300650789_Building_a_Hybrid_Reactive_Rule_Engine_for_Relational_and_Graph_Reasoning

There is a blog with presentation about this:
http://blog.athico.com/2015/08/ruleml2015-hybrid-reactive-relational.html

And here is a list off issues related to OOPath:
https://issues.jboss.org/issues/?jql=project%20in%20(DROOLS%2C%20RHBRMS)%20AND%20labels%20%3D%20oopath