CA-149969: EN: Inappropriate error message pop up by entering invalid port number.
Merge pull request #272 from GaborApatiNagy/CA-149969

CA-149969: EN: Inappropriate error message pop up by entering invalid po...
CA-154651: Bump API version number
Merge pull request #277 from stephen-turner/CA-154651

CA-154651: Bump API version number
CA-150338: Importing system template causes XenCenter to throw an exception
-Fixed NullReferenceException