This reverts commit a517dc20.

This reverts commit ec01253e, reversing
changes made to ae8c9710.

@jzoldak showed me that setting `USE_I18N = DEBUG` didn't actually accomplish
what I had hoped it would -- changing DEBUG didn't also change USE_I18N.
This pull request accomplishes what I was trying to accomplish, without being
quite so clever about it.

as a first step to separating db connection from modeling
and to support location mapper and contentstore using same db config as modulestore

use to instantiate loc_mapper
test loc_mapper injection into split modulestore

add a few debug messages to get localhost debug information. Also partition out the MongoDjangoToolbar configuration into a separate env config. This is because doing imports on large courses grinds localdev to a halt due to all the stack trace generation.

not common.  This ensures that we load the MITX_FEATURES
token BEFORE deciding to disable CSRF.

A new modulestore backed by mongo that changes the data format to
facilitate easy versioning, sharing content between courses, and fast
lookup of course structure and Scope.settings data.

Conflicts:
	cms/djangoapps/contentstore/tests/test_contentstore.py

add a new cms ENV configuration to use a slow upload file handler to help test progress bars in uploads

DraftModuleStore was originally designed as a mixin, but never used that
way, and with the upcoming changes to use the versioned module store,
never will be. This changes removes a circular dependency between
mongo.py and draft.py.

add new collection configuration to support a 'trashcan' for assets. Update class factory to allow callers to specify if they want the default set of assets or the trashcan

Make django use_tz

Developers can have private settings files by creating
lms/envs/private.py or cms/envs/private.py.  They are imported
at the end of dev.py.  Note that they won't be imported if you
are using one of the other dev*.py variants.

PREVIEW_LMS_BASE must now be set (default value does not work for both edge and edx). Make this work locally as well.
https://edx.lighthouseapp.com/projects/102637/tickets/331

Start linting envs files, add task to only pylint errors, and move pylintrc file to the correct location

Change the parameters of the sass compiler to output source
maps. Google Chrome uses the maps in the debugger to show the sass or
scss file that originated the style for a particular element.

More information here:

http://fonicmonkey.net/2013/03/25/native-sass-scss-source-map-support-in-chrome-and-rails/

Have to explicitly specify safe option on mongo insert, remove, update because the debug toolbar specifies a default of safe=False.

use django caching to hold computed metadata inheritence. Also invalidate the cache entries on writes (insert, updates)