Fix exception to support unicode (and print url_name).

Part of STUD-868
Support unicode in text field.

Part of STUD-868
Support non-ascii chars as arguments to format.

We've had errors in export related to non-ascii chars being passed to format. Proactively making these usages of format robut to non-ascii chars.

Part of STUD-868
Add better messaging, turn off SSL verification when sending grade back.
Merge pull request #1987 from edx/oleg/fix_mock_lti_protocols

Fixes and improvement to LTI.
Merge pull request #2018 from edx/christina/export-bug

Bug fixes related to unicode support in export workflow.
Merge pull request #2020 from edx/christina/export-bug2

Support non-ascii chars as arguments to format.