Addition of cobertura and surefire parsers

I have added support for parsing of surefire and cobertura reports to the scala plugin.

These reposts are generated by scct (cobertura xml) and the simple junit report plugin (junit xml).

I had a pull request merged to fix some issues with the junit reports, however there is still a bug with the cobertura report generator that requires a workaround in the cobertura parser. I have added a unit test for the workaround, and documented it with a TODO for deletion once either Mikko or myself can fit the scct plugin.

This is my first contribution to Sonar, so if you notice any major issues, please let me know.