adding event tracer stubs

git-svn-id: https://svn.wso2.org/repos/wso2/carbon/platform/trunk@190387 a5903396-d722-0410-b921-86c7d4935375
updating the create_ds.png

git-svn-id: https://svn.wso2.org/repos/wso2/carbon/platform/trunk@190388 a5903396-d722-0410-b921-86c7d4935375