LSNBLDR-385; fix validation problems for both import and export of essay questions (two separate edits for trunk and 2.10)


git-svn-id: https://source.sakaiproject.org/svn/lessonbuilder/branches/lessonbuilder-1.4.x@310349 66ffb92e-73f9-0310-93c1-f5514f145a0a