Reporting commons

WINDUP-120. Prereq for WINDUP-128.
1) The annotations
2) Classes to be shared for Solution and Reference
3) Models for Rule and RuleProvider
Please avoid nested public types. Couldn't this be replaced by a boolean value on the @Property annotation itself?

`@Property(skip=true)`

or we could use an existing JAXB annotation for this, right?

`@XMLTransient?`

Or a javabeans existing annotation:

`@Transient`