Add DataPublisher cache and Endpoint metadata class
Deligate stop method from direct DataPublisher to Stream
Wrapp all WSO2 exceptions with self exception. API separation.
Merge branch 'master' of https://github.com/ikonovalov/wso2dp4wmb

Conflicts:
	src/main/java/com/lux/wso2/WMBEventsAdapter.java
	src/test/java/com/lux/wso2/DataPublisherHolderTest.java
Merge branch 'master' of https://github.com/ikonovalov/wso2dp4wmb

Conflicts:
	src/main/java/com/lux/wso2/WMBEventsAdapter.java
	src/test/java/com/lux/wso2/DataPublisherHolderTest.java