Only copy over the jquery.ui packages we actually need.

Summary: This list is from alpert.  I don't know how to test it's sufficient.

Test Plan:
Ran
   python -mSimpleHTTPServer
and visited
   http://localhost:8000/exercises/absolute_value_equations.html
and got the question wrong, and verified when I clicked on 'Check
Answer' the answer box still shook properly.

Reviewers: alpert, eater

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D2498