Bonjour - Fix memory leak and service rediscovery

The QSocketNotifiers for the resolver and address were not being deleted in
cleanUp().  This would cause a memory leak and also prevent a service from
being rediscovered after removed and added back on another device.  I
suspect the undeleted QSocketNotifier was holding a file descriptor open
which would break things.  Should fix

issue #27
Power-Cycling Bonjour Devices Can Cause Permanent Loss
https://github.com/jbagg/QtZeroConf/issues/27

and pull request #34
macOS: Fixed undetected service stop/start while the application is running
https://github.com/jbagg/QtZeroConf/pull/34

bonjour.cpp

@@ -47,6 +47,8 @@ void Resolver::cleanUp()
 {
 	DNSServiceRefDeallocate(DNSresolverRef);
 	DNSServiceRefDeallocate(DNSaddressRef);
+	delete resolverNotifier;
+	delete addressNotifier;
 	QString key = zcs->name() + QString::number(zcs->interfaceIndex());
 	ref->resolvers.remove(key);
 	delete this;