QPID-5829: Properly fix the CMake conditional

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1603067 13f79535-47bb-0310-9956-ffa450edef68
QPID-????: Refactored Broker::Options into its own independent class
- Now called BrokerOptions
- Added extra getters to Broker so that nothing else needs to know
  about BrokerOptions
- Significantly reduces header coupling as lots of files include
  Broker.h, but now don't need Options.h