Fixes #14585 - added long overdue syntax error handling

git-svn-id: http://svn.dojotoolkit.org/src/dojox/trunk@30331 560b804f-0ae3-0310-86f3-f6aa0a117693
(cherry picked from commit cf816f79bfc41a293027ea114eb9370d74ff299b)

Conflicts:
	form/Uploader.js
	form/tests/test_Uploader.html
	form/uploader/_HTML5.js
	form/uploader/_IFrame.js