TNL-4001

We now hide "scores" of 0/0, since those aren't really scores at all.

Also adding acceptance test to handle a problem with an unscored (feedback only)
criterion, in addition to verify the above hiding of 0/0 scores.

Previously, we were only showing the "more assessments needed" message
when there were 0 assessments, but we also need to show it when there are
0 < n < must_be_graded_by assessments for the user, to prevent a blank
area on the grade report. We also supress feedback comments from peers in
this case.

TNL-3930, TNL-3761

The crux of this fix is that scored_only behavior in various api/peer.py
methods is no longer needed, or correct. This value has been removed, so
that assessments may be gotten (and medians found) when the assessments
are not used in determining the final score (say, if a staff score exists).

Also includes updates to the "waiting for steps" string as prescribed by
@catong in https://github.com/edx/edx-ora2/pull/764, along with logic for
that method, and updates to tests and get_wating_details logic in light
of this simplification.

TNL-3465

- Allow image, pdf-image, or custom file types
- Global black list extensions to prevent unsafe file types
- Custom file upload is white listed only

# Conflicts:
#	AUTHORS
#	openassessment/templates/openassessmentblock/edit/oa_edit.html
#	openassessment/xblock/static/js/openassessment-lms.min.js
#	openassessment/xblock/static/js/openassessment-studio.min.js
#	openassessment/xblock/static/js/spec/lms/oa_response.js
#	openassessment/xblock/static/js/src/lms/oa_base.js
#	openassessment/xblock/static/js/src/lms/oa_response.js
#	openassessment/xblock/static/js/src/oa_server.js
#	openassessment/xblock/static/js/src/studio/oa_edit.js
#	openassessment/xblock/static/js/src/studio/oa_edit_settings.js
#	test/acceptance/tests.py

TNL-2000

TNL-900

Currently, Latex rendering is only supported for question prompts in ORA2. This
commit introduces Latex rendering in ORA2 student response, peer assessment
view, self assessment view, grade view, and staff-info view. The reason that
this Latex rendering code is inserted directly into ORA2 is that edx-platform,
does not know when to start Latex rendering for ORA2 views that come in via
AJAX.

This commit introduces "Preview in Latex" feature which allows students to see
their response rendered in MathJax before submission.

Conflicts:
	openassessment/xblock/static/js/openassessment-lms.min.js
	openassessment/xblock/static/js/openassessment-studio.min.js

Point setup instructions to the README

Add instructions for combining/minifying static assets

Update workflow overview architecture docs

Update AI grading architecture docs

Use napoleon keyword argument instead of kwargs

Fix example usage docstrings in AI API

Changed the template for rendering feedback to encorporate self feedback, and changed the handler to provide appropriate context

Update container JS to retrieve both name and label for criteria and options

Update schema to make 'name' optional and 'label' required; the XBlock editor handler assigns UUIDs to criteria and options that don't have names

Assign labels to criteria/options if they do not have any

Update the grade template to display criteria/option labels if they're provided, otherwise use the 'name' field

Update student facing rubric templates to display the label if it's available

Add label field to XML problem definition.

Add label field to assessment

Add label field to the data dump script.

Update the turbo mode template to use option labels

Exclude the "name" key for new criteria and options in the JSON dict sent to the server.
Default new option points to 1 instead of NaN

Add data migration to fill in labels with default values

Move openassessment out of the apps directory
Use pkg_resources to check whether OA XBlock is installed.

Move self_api.py and peer_api.py into an api subpackage

Split serializers.py into serializers/base.py and serializers/peer.py

Move errors for assessment app into a module.

This also creates the AssessmentWorkflowStep model to track all
steps for new workflows. Some problems with it now:

* a lot of broken tests
* some display oddities on the peer step during (peer, self) workflows
* have not tested to see if there are concurrency issues with step
  model creation under load.

Remove unused start/due date args in xml parsing
Use textarea attribute to limit submission/feedback text length instead of JavaScript checks.
Server truncates submissions/feedback that are too long instead of raising an exception.
Refactor peer step JS into its own source file.
Move JS namespace and gettext stub into a shared file.
Add scrollTo for turbo grade submission.

Edit error messages in .py files
Corrected tiny typo in models.py
Revise UI and error message text in .js files
Updated "Could not contact server" error messages

This introduces a few features:
* INFO level logging on common events like creating or fetching
  submissions and assessments.
* Parallel event logging for the same.
* Creates a local logs/ directory for development.

For the most part, we rely on XBlock's publish() mechanism to emit
event data. However, because scoring is done at the API layer in a way
that is not directly visible to the OpenAssesmentBlock, we're logging
that event separately with a hacky solution that dynamically loads an
emit function based on a configuration value. This is a stopgap
measure until we can start using the edX analytics API (which is still
in testing).

TIM-260, TIM-378

* provides static states for submission cases
* adds in abstracted system-feedback sass partial
* adds in starter animation sass partial
* syncs up loading style for steps with standards
* moves message UI archetypes/variables to the xblock level of Sass architecture

Move JS grade step into a separate file
Feedback on submission UI wiring

* Improved error handling and reporting

* remaining items:
 - replace submission fk w/ m2m on peerworkflowitem
 - complete move
 - initialize feedback box, grayed out
 - tests

* TODO: incomplete move, usage still in submissions api