Add RequireJS Optimizer.

**Ticket:** [TNL-481](https://openedx.atlassian.net/browse/TNL-481)

**sandbox:** http://studio.polesye.m.sandbox.edx.org/
**New Relic Page:** https://rpm.newrelic.com/accounts/88178/browser/4020167/v2_page_views
### Requests count:

Page  | Before | After
------------ | ------------- | -------------
[Dashboard](http://studio.polesye.m.sandbox.edx.org/course/) | 54 | 35
[Outline](http://studio.polesye.m.sandbox.edx.org/course/edX/DemoX/Demo_Course) | 66 | 37
[Container](http://studio.polesye.m.sandbox.edx.org/container/i4x://edX/DemoX/vertical/vertical_98cf62510471) | 114 | 55
[Advanced settings](http://studio.polesye.m.sandbox.edx.org/settings/advanced/edX/DemoX/Demo_Course) | 57 | 35
[Textbooks](http://studio.polesye.m.sandbox.edx.org/textbooks/edX/DemoX/Demo_Course) | 62 | 34

FYI: https://docs.google.com/a/edx.org/document/d/1pIyEaZ_bldy9riaXle0d59D_onJ7I_hISPqG0rhNIj8/edit#heading=h.lgqntoce8jlj

@andy-armstrong , @jimabramson , @cahrens , @tymofij  please review.
Is there no way to dynamically create the list based on the contents of the factories directory? It seems like this list will easily get out of sync.