Configuration revamp - use of new AndesConfigurationManager for accessing properties.

Use new AndesConfigurationManager class to access andes-specific properties. 

Rename andes-config.xml to broker.xml and move qpid configurations to qpid-config.xml. 

move andes configurations to broker.xml and abstract qpid-virtualhosts.xml. 
This is fixed with https://github.com/wso2-dev/andes/pull/180