[BZ-1073880] run timed rules in a single thread executor
BZ-1072774 - NPE when I register a workitem handler
DROOLS-440: adding JMX management mbeans to kie scanner
DROOLS-440 : adding shutdown method to KieScanner implementation. Making KieRepositoryScannerImpl thread safe.
DROOLS-440: enabling/disabling mbeans through system property