This reverts commit 544616be.

To get all dates localized, we need all runtimes to have the i18n
service, and since runtimes are made by the modulestores, we need to
pass it to them.

Soon (fingers crossed), modulestores won't be involved in making
runtimes, and many of these changes will go away.

This requires fixing the javascript api implementation, and adding
an implementation of get_block to the ModuleSystem api.

However, the implementation is incomplete, due to mismatches between
the expectations of XModule and XBlock.

Also adds tests using the Acid block to make sure that the javascript
and python apis for children are working correctly.

The Video element contains an input with type file. When the
Check button was clicked for the multiple choice problem, the
code was acting in different ways when there as a Video on the
page and when there wasn't. This is because in the check_fd()
method there was a selector that was looking for inputs of type
file on the whole page instead of just in the current problem.
When there was a Video pn the page, the page-wide selector
returned the Video's file input, and the check_fd() method
went on believing that the multiple choice has a file input.

The correct way is to look for file inputs only in the current
element.

Added a Jasmine JavaScript unit test.

BLD-788.

STUD-1133

Due to issues with require.js and the latest version of the toolbar.
Also included a note in the requirements file explaining the situation, and what
needs to happen before this can be upgrade properly.

Restore reverted changes from paver part 1

Fixed bok-choy acceptance tests

* Don't show sidebar if only one language is present
* only add in the default language code if it's not already present

instead of the current language.

Also, refactor tests such that we're not deleting users or prefs

Will pass once the language persistence stuff gets merged in

make openendedchild and open_ended_module_v1 act enough like xblocks to get xblock 18n