adding scheduling support
updating constants needed for scheduling support
fixing generate scheduling frequency
Merge remote-tracking branch 'origin/master'

Conflicts:
	siddhi-hive-component/org.wso2.carbon.siddhihive.core/src/main/java/org/wso2/carbon/siddhihive/core/headerprocessor/TimeWindowStreamHandler.java
	siddhi-hive-component/org.wso2.carbon.siddhihive.core/src/main/java/org/wso2/carbon/siddhihive/core/internal/SiddhiHiveManager.java
unused imports