Bug 270018

Effect:

* Compilation errors shown in IDE (not in Maven build) for JPA ModelGen classes (the genererated classes are inside in another submodule called ‘entities’)
* Unit test does not work from inside the IDE
* No guidance / support in the IDE for annotations.

It seems that :

1.	Its required to mark annotation processors as provided Maven dependency. The 'new' annotationProcessorPaths in the configuration of the maven-compiler-plugin was introduced to keep annotation processors from the class path of the project code itself.

2.	If I need to manage the annotation processor dependencies as provided , I would like to manage them centrally, so I can remove them whenever point 1. is solved.

But: I also noticed, that adding the annotation processors are not picked up the <dependencies> (not <dependencyManagement>) of a parent pom which has <relativePath /> empty (which you would like to do if you maintain a baseline or bom). They are however shown as set when you look at the effective pom. Moreover, it works when you have a non-empty <relativePath> pointing to the parent.