[FIXED JENKINS-9637] Fixed the 404 when clicking the testResult on the Project Page when there is only an aggregated test result.

[FIXED JENKINS-9637] Fixed the 404 when clicking the testResult on the Project Page when there is only an aggregated test result for a freestyle job. The name of the link is still wrong.
Moreover, no test trend is shown for the aggregated test result and the method "getAggregatedTestResult" never returns the aggregated test result of the Publisher. See also the discussion https://groups.google.com/forum/#!topic/jenkinsci-users/xgcTIhfrXMk on the mailing list.