Use Jacoco for the Quality Profile

The main reason is that Jacoco is faster than Clover. For example on commons component api it took 6 seconds with Jacoco vs 9 with Clover.

The other reason is that Jacoco doesn't instrument source files which makes it better suited for a build since it won't generate clovered artifacts in your local repository which can then be pushed to production by mistake for example.

Note that we need to wait for version 0.6.1 of the Maven Jacoco plugin to be released to be able to implement this since the new check mojo has been added in 0.6.1, see https://github.com/jacoco/jacoco/commit/d45e77440ce6cfbdc1bca827b55f11fef6e9bdf7