Adding Concat operation
Merge branch 'master' of https://github.com/wso2-dev/developer-studio

Conflicts:
	data-mapper/org.wso2.developerstudio.visualdatamapper.diagram/src/dataMapper/diagram/edit/parts/InputEditPart.java
	data-mapper/org.wso2.developerstudio.visualdatamapper.diagram/src/dataMapper/diagram/edit/parts/OutputEditPart.java