Update Jacoco plugin config

* Use newer version
* Use jacoco.destFile property rather than configuration settings
* Allows managing 2 or 3 deeps project easily (just override
jacoco.destFile in the pom)
* Default value of jacoco.exec is still ../../target/jacoco.exec,
which fits single-component modules (such as webservices). Other
multi-component modules need to set it to ../../../target/jacoco.exec.