Migrate to Sonar 3.0 Plugin API. Stop using commons-configuration and use org.sonar.api.config.Settings instead.

Update sonar.minversion to 3.0 and stop using deprecated commons-configuration within sonar-scm-stats. Migrate to org.sonar.api.config.Settings instead.

Manually disabled/enabled the SCM Stats plugin using the UI and confirmed it continued to behave as expected.