Merge pull request #22 from christ66/master

Fix unstable job portlet to properly display items inside folders.
[FIXED JENKINS-21578] Ensure that ${jobs} is really a Collection<Job>, with no Folder for example.
Merge pull request #23 from jglick/folder-CCE-JENKINS-21578

[FIXED JENKINS-21578] Ensure that ${jobs} is really a Collection<Job>