* Convert to using ExitStack instead of nested.

nested is not available in Python3.

* Use ExitStack from contextlib2.

ExitStack has not been backported to the Python 2.7 standard library and
contextlib.nested is no longer available in Python 3.5.  We need to be
able to use something in both 2 and 3 as we transition so we'll pull in
contextlib2 which has backports of the full python3 contextlib.

Fix more test collection.

We stopped using it but forgot to remove it from the import.

Added edx-when's FieldData

EDUCATOR-4554
This fixes a bug where extended due dates were visible in the outline but not reflected on the courseware pages, resulting in problems not being submittable past the due date.
In order for edx-when to work on courseware pages, it has to be more careful about field inheritance, which version 0.2 achieves.

BOM-85

BOM-83 Removed usages of bulk_assertion

removed usages of bulk_assertion

changes made to comply quality failure

removing test-bulk assertions.

Override theme with site_theme query param

he builtin basestring abstract type was removed. Use str instead.

BOM-84

Don't jam LOGIN_REDIRECT_WHITELIST into devstack_docker settings, we already define it in devstack (and we read private.py from devstack).

Feanil/upgrade mongodb proxy

BOM-70

Update the version.

BOM-79 

Revert "[BB-873] Support for filters, and multiple roots in problem response reports"

More test collection fixes.

[BB-873] Support for filters, and multiple roots in problem response reports

-Remove Depricated View and tests

BOM-80

Revert "BOM-70"

Downgrade newrelice version from 5.0.0.124 to 4.20.1.121.

This change adds support for specifying multiple root blocks while generating
problem response reports. It also allows specifying a block type filter so that
only blocks of the filtered types will be included in the report.

Finally, this change also consistenly uses absolute path for the location in the
report instead of relative paths.

Getting 500 error on stage after upgrading to latest version
of newrelice.

BOM-82

BOM-81

openedx.core.djangoapps.ccxcon.tasks.update_ccxcon is not get auto
discovered by celery. Adding it to CELERY_IMPORTS to be explicitly
added.

PROD-283