Easily disable / exclude transitive dependencies

Transitive dependencies are cool, however, the limitations are very difficult to work around.

• specification dependencies
• jarjar dependencies (spring.jar includes all spring-xxx.jar, so no need to include them)
• remove warning on relocations for transitive dependencies (it's always difficult to tell users: that's not an error, and we can not do anything)
• poms on ibiblio are all in m2 and never change
• exclusions for transitive deps can be overriden if manually included

One cool feature would be to allow disabling transitive dependencies in the following ways:

• disable all transitive deps
• enable transitive dependencies only for modules of the same project
• enable transitive deps for specific groupIds
• disable transitive deps for specific groupIds
• have a tag/attribute to exclude all transitive deps for one dependency (instead of having list all exclusions)