Lots of validation improvements/fixes
More validation fixed, added CANLEAD to trusted LTI origins
Removed character limit from course description
IF LTI
	-dropped breadcrumbs
	-droped sidebar expect recent posts
Fixed method for caputring LTI origins
Search now fully case-insensitive
Improved error handling for LTI launches
Fixed typo in discussion.php
Adapting Sam's work on LTI