As question preview window is small, chrome driver
fails to select drag and drop element

DND question types use switch window and the tag
was not added, so it was failing for phantomjs
Added tag to avoid phantomjs failures

A recent bugfix before integration left this failing. They are 22.

Credit to Andrew Nicols.

All of these changes make use of already
fetched grade data.  Without these changes,
the gradebook regrade process does not scale
well with very large courses because it fetches
many grade records, one at a time.

Note: Fixed some minor grunt and EOF whitespace issues while merging.

We previously had a global Y (simpleyui) and a separate Y created
to put Y in scope for all our modules. This meant that we had 2
separate sandboxes for YUI, which means that modules are duplicated,
and events do not fire across YUI instances.

This change merges the 2 instances, so any code refering to Y will
get the same instance of YUI (amd code, yui modules, static init code etc).

Thanks to Andrew Nicols!