[SERVDEV-22]
- Refactored InferedKettleOutput to remove unnecessary code.
- Removed unnecessary get/setKettleType methods from IKettleOutput and respective implementations.
- Removed unnecessary get/setOutputStepName methods from IKettleOutput and respective implementations.
- Corrected possible NullPointerException on KettleElement.processRequest(  Map<String, String>, String, String, boolean, boolean, HttpServletResponse ).