Shared LMS cookie should be shared across all pages

Fixes an issue where the LMS would return an error 500 in certain conditions.

The issue was that the shared session cookie path was set to the first page from the client UI on which an XBlock was loaded, instead of `/`, which would prevent the session id to be passed, and resulting in not being logged in on the LMS, which would crash certain XBlocks.
Group resources by hash tag to avoid duplicate loads
Load resources sequentially, in the order sent by the LMS
SITENAME is already included in resource.data
Support for resources that don't contain the SITENAME
Merge pull request #2 from aboudreault/resources-urls

SITENAME is already included in resource.data
Added a test environment and created tests
Minimized the javascript resource mock file
Added a Makefile to run tests
Added a test for the submit button
Make ajax mock to use javascript fixture files