Merge pull request #18 from Gayany/master

Introducing data mapper configuration dialog
Modify the existing Concat operator to have any number of inputs.
Merge pull request #16 from wso2-dev/master

Merge pull request #18 from Gayany/master
Merge pull request #19 from lsdeva/master

Modify the existing Concat operator to have any number of inputs.
Merge pull request #18 from wso2-dev/master

Merge pull request #13