undo adding .gitignore to itself

This reverts commit acfd0d9f, reversing
changes made to e4194c99.

This reverts commit 57427f9a, reversing
changes made to 37621c26.

Master went from 5d912b88616f05c5ec10e89b336bd1088042bba0 to
e43c2bd4. 5d912b8a is a merge commit
that merged a branch onto master, so I am merging the same commit
back into master.

Move Pearson login to external_auth

* hide the login behind a setting that is turned off by default
* clean out some of the outdated settings and hardcoded test strings

Make sure to run :predjango before gather_assets so that the xmodule_ass...

Speed up local development

Speed up testing by running pylint in fewer batches

Feature/i18n

use new API verbs

Only render a histogram for modules that have scores associated with the...

Doc/showanswer

Allow course staff to masquerade as students in viewing courseware

Feature/will/update testing docs