PIT Mutation Tool Integration

[SteGaff7]

Hi I have been using PIT mutation tool in conjunction with Defects4j framework as part of my research project. It is not the cleanest integration and there are a lot of redundant lines of code but it offers a functional version of defects4j with PIT mutation. I have integrated PIT into the defects4j.build.xml file and edited each projects own build file to provided additional ant properties that don't clash with the properties needed for other tasks. I have also added 2 scripts run_pit.pl and run_pit_dev.pl.

This integration was purely for research purposes so it may not be as clean as desired but I thought you might be interested in integrating it further.

Also this is my first pull request so I hope all is in order with it.

Thanks Stephen

[rjust]

Hi @SteGaff7,

Thanks for setting up this PR!

Can you please remove the libraries from the PR and download/initialize external tools and required dependencies in the init.sh script (e.g., similar to how the init script downloads EvoSuite and populates framework/lib)? I am happy to then take a closer look and provide more detailed feedback.

Thanks, René