This removes the vote button from threads on the user profile, which was
the only interaction available on the page other than the link to view
the thread in the main discussion view.

JIRA: FOR-429

1. Add space between threads
2. Change Show/Hide to Expand/Collapse and visually separate it
3. Limit a thread to 700px high and scroll if longer

Co-authored-by: marco <marcotuts@gmail.com>

Students no longer see a tooltip nor any button affordance (i.e. cursor
and color change on hover/focus) on the pinning feature. For moderators,
the tooltip is now correct when a thread is pinned, the button is
accessible for keyboard-only users and screen readers, and an error
dialog now appears if an error occurs in attempting to pin/unpin.

JIRA: FOR-192

screen readers. Also, the mathjax message should be wrapped to prevent
non-IE browsers from complaining about a feature that is IE-only.

LMS-2156

Users will first be shown the first 25 responses of a viewed thread and
then have the option of loading 100 more at a time until all responses
have been loaded. This mitigates the performance impact of very large
threads by avoiding the need to render and transfer over the network
all content of a large thread at once. It will also allow students with
slower browsers to interact with large threads even if they cannot load
all of the responses.

- Clarify checkbox description wording
- Wrap checkbox and envelope icon in div to make it stand out
- Added styling for wrapper div
- Wrap label element around div to allow clicking the envelope to activate the checkbox
- Indented HTML and fixed if wrapping issue

JIRA: FOR-373

JIRA: FOR-400

JIRA: FOR-205

Also get rid of an unused template and extra copies of jquery.timeago.

JIRA: FOR-398, FOR-399

This change involves substantial refactoring of the relevant code to
reduce duplication. It also makes the templates for the vote buttons
more consistent and cleaner.

JIRA: FOR-64

A newer version was added to common/, so that is used instead. It is
also added to the set of JS files used in unit tests to allow forums
code in common/ to be tested.

This button has been broken for at least a year, so the code has
suffered from bit rot and should be reimplmemented if the feature is
necessary in the short term (which is unlikely since it has been broken
for so long).

The show/hide toggle now properly acts like a button, and focus is now
trapped on the loading element for both the show/hide action and loading
of a new page.

They now include screen reader-friendly text, have the ARIA checkbox
role, activate on keypress (for space or enter), and occur in the DOM
after the header information (title, etc.)

The "Report Misuse" div is now focusable, responds to keyboard input,
and has appropriate attributes to indicate that it is a toggle button.
This fixes FOR-201 and FOR-209.

update discussion forums views to add accessibility information and add hidden accessibilty class to discussion scss, this comprises adding comments count and votes count verbiage and vote call to action

Add the aria-haspopup attribute and additional explanatory text for
screen reader users.

LMS: resolves direct class name references to extends that have been converted to placeholder Sass syntax

Previously, if a course id contained a '-' character, links from that
page to threads would lead to 404s.