BLTI-274 changes in the filterForm logic to deal with autodate type fields. Also fixed a problem that LTI tool cannot created because of the missing site_id field in the LTI admin tool

git-svn-id: https://source.sakaiproject.org/svn/basiclti/trunk@129307 66ffb92e-73f9-0310-93c1-f5514f145a0a