Revise MODCLUSTER-332 fix.
Remove unused Engine.getBackgroundProcessorDelay() method.
Replace ambiguous org.jboss.modcluster.container.catalina.WAITSTATUS system property with more intuitive org.jboss.modcluster.container.catalina.status-frequency property which indicates the frequency with switch to perform STATUS processing with respect to the backgroundProcessorDelay..
Convert tab indentation to spaces.