Add Cobertura code coverage reporting
Add Cobertura code coverage reporting

There are three new ant tasks: instrument, clean-instrument, and
coverage-report. You need to use clean-instrument or clean to get back
to a non-instrumenting state. To use the reporting, you need to get
Cobertura and place it at ../cobertura relative to your plexi checkout.

dweidenfeld/library,joesoc/plexi,googlegsa/library,joesoc/plexi,googlegsa/library,dweidenfeld/library,joesoc/plexi,joesoc/plexi,googlegsa/library,dweidenfeld/library