Move inter-JBT dependencies to component poms

It has been discussed several times that the composite site is a kind of "weak point" in our build chain, because it allows cyclic dependencies, and it also introduces indirections that make it less straightforward to find out what a project should/does depend on to build.
The benefit of composite now seem a bit light: it's cool because we can put it in parent pom and all builds succeed to get there dependencies, but out of that, there hasn't been much other use-cases. And as we want to provide more and more autonomy to project, this composite site they'd depend on is something that doesn't make them autonomous.

So the idea is to move dependencies to project root poms. I've made a draft of how it would look like in project pom if we remove the "jbosstools-site" from parent pom and let projects manage their inter-dependencies: https://github.com/mickaelistria/jbosstools-javaee/tree/JBIDE-16309
You can try this by running "mvn clean verify -P!jbosstools-site". The "-P!jbosstools-site" disable the jbosstools-site profile, which is the one controlling addition of the composite or ggregate to the resolver
https://github.com/jbosstools/jbosstools-build/blob/master/parent/pom.xml#L423