formulaequationinput: add capital greek letters and hbar to calc preview
Remove unused XModuleDescriptor.get_sample_state method
Fix forums nav sidebar overlapping content

Previously, when the window was scrolled down past the top of the
discussion content pane, scrolling right would cause the sidebar to
appear above the background of the content pane but below the text.
This is only an issue with very small windows or with the text size
increased significantly, which is why this came up in an accessibility
audit. Now the sidebar is fixed to the left side of the page instead
of the left side of the viewport.
Make default parser keep comments
LMS: resolves header logo and global nav inheriting verification reset link styling
Remove due date setting
Implementing NYT's ICE track changes to Open Ended Assessements

Squashed commits to facilitate cherry-picking.  Committers and
original commit messages are:
- ==> @caesar2164, * ==> @jrbl, ~ ==> @jbau

- Added boolean to OE problem CMS settings to turn on ICE track changes
- Added ICE init and tracking start/stop to HTML
- Conditional in Peer Grading HTML for ICE container
- CSS styling for ICE container and insertion/deletion elements
- Added class to track changes HTML
- Added ice.min.js as well as included it in the js requirements for peer grading
- Use track_changes in peer_grading_problem
* Refactor peer_grading_problem to lookup track_changes variable by problem location.
* Whitelist ICE insert, delete tags
* Adds ICE multi-user-editor insert and delete tags to the peer grading sanitize_html whitelist.
- add reset button

* Introduction ICE means we need its inline tags to get passed through
  to the feedback target, but we don't want malicious peer feedback
  providers introducing <script>, etc, so we use lxml.html.clean to
  scrub peer grading input.
* Adds feedback URL autoheating.
* Allows ICE <insert> and <delete> tags but not others.

~ add helptext re: EXPERIMENTAL FEATURES

~ address a bunch of @VikParuchuri review comments on ICE for OEE
  ~ remove extraneous code
  ~ change to new xmodule accessors
  ~ refactor filtering

~ fix broken test test_peer_grading_problem

~ Create track_changes.coffee and remove <script> from
  peer_grading_problem.html
~ Remove all reliance on id in favor of local scoping and classes

~ bring up test coverage somewhat

~ remove superflous $.scrollTo

~ TODO: Filtering
Merge pull request #956 from edx/giulio/ice-pr

Implementing NYT's ICE track changes to Open Ended Assessements
Merge branch 'release'
fix default for VERIFY_STUDENT in lms/envs/aws.py
Convert JSON dumps output to UTF-8 before sending to Software Secure
Extend message signing code to work with dicts, lists.
Replace signature validation with access-key and add logging around Software Secure callbacks.
Update docstring on ssencrypt.body_string to be more useful.
Merge pull request #919 from edx/jkarni/fix/keep-comments

Make default parser keep comments
Merge pull request #994 from edx/ormsbee/ss_msg_signing2

Software Secure message signing pt. 2
Merge pull request #982 from edx/talbs/fix-lms-header

LMS: FIX - Header Logo and Global Nav Styling
Disabled broken test in master.
Merge pull request #997 from edx/will/disable-broken-test

Disabled broken test in master.
4 OE/ORA UI fixes to make it easier to use
- require confirmation when clicking Open Ended reset button
- require confirmation when submitting Open Ended essay
- disable text feedback area during calibration and let users know that they should give feedback when grading
- fixed error message typos