Maven 1.x Clean Plugin

When doing a maven clean the maven.build.dest dir isn't cleaned.
This can cause a lot of errors:

• When refactoring, the new and old files are both in the maven.build.dest.
• When changing the resources the old resources are still in the maven.build.dest.
• In some cases you get exceptions because some classes aren't recompilled when they should.
• When having multiprojects like the maven plugins the building process is often broken because one of these errors.