Split up report into two targets: one for tools, one for filtering/report generation

[amessner]

The JcReport ant task should support running the check tools and producing the actual report in two steps. This would be helpful for parallelization scenarios, where one wants to run the tests (producing coverage output) and in parallel create the check tool reports. In this case it would be necessary to merge the tool and coverage results in an extra step.

[mrumpf]

Closing the ticket. If necessary, a new ticket will be created for the Maven 2.x milestones.