Add possibility to fail the build on any severity issues

[david-m-s]

Currently the build only fails when errors are detected, but I need it to fail on warnings too. I tried configuring pmd and checkstyle individually but I was not able to make them produce error level instead of warning. Also even if that might be possible requires coupling to how the particular version is configured, which may be difficult to maintain.
I have created MR #478 to add new parameters for the warning and debug severities and made the additions backwards compatible. Please take a look.