adding changes related to WSExecutor

git-svn-id: https://svn.wso2.org/repos/wso2/carbon/platform/trunk@182184 a5903396-d722-0410-b921-86c7d4935375
refactoring WSExecutor

git-svn-id: https://svn.wso2.org/repos/wso2/carbon/platform/trunk@182185 a5903396-d722-0410-b921-86c7d4935375