Improve MAVEN build Performance

Maven allows you to run the compiler as a separate process by setting <fork>true</fork>. This feature can lead to much less garbage collection and make Maven build faster. This project has more than 1000 source files. We can consider enabling this feature.

===================== If there are any inappropriate modifications in this PR, please give me a reply and I will change them.

According to the conversation here, it leads to non repeatable compilation operation.

I'm reluctant to switch this on because we've had many problems in the past with reproducibilty of tests, mostly because of other issues, like abuse of singletons. See a related conversation: #103

In any case at best this would provide a minor gain in test performance.