Responses to Adam's comments; reset common.py, i18n compliance, deleted extraneous email.html file, fixed an HttpResponse, deleted unnecessary commented-out code, some small style tweaks

The icons and text for pinning and flagging ("Report Misuse") had
contrast ratios that did not meet the minimum WCAG requirement of 4.5.
This fixes FOR-200.

Responses to Adam's comments; reset common.py, i18n compliance, deleted extraneous email.html file, fixed an HttpResponse, deleted unnecessary commented-out code, some small style tweaks

LMS: adds message styling to the separate instructor_2 Sass file

- Changed save OE message text
- Fix ICE legend positioning and content
- Add space to "offensive" checkbox
- Change tracker variable in undo to correct one

Previously, colors changed to afford interaction only on hover; now, all
elements with a hover color change behave the same way on focus.

With tests, some settings changes
(all should default to not breaking anything for edx)

Added styling for shopping cart User Experience
- Styled shoppingcart list page
- Styled navigation shopping cart button
- Styled receipt page
- Styled course about page for shopping cart courses

Addressed HTML/SCSS issues

Remove offending body class and unnecessary sass changes

Addresses many review comments on stanford shopping cart

* framework for generating order instructions on receipt page
  in shoppingcart.models
* move user_cart_has_item into shoppingcart.models
* move min_course_price_for_currency into course_modes.models
* remove auto activation on purchase
* 2-space indents in templates
* etc

revert indentation on navigation.html for ease of review

pep8 pylint

move logging/error handling from shoppingcart view to model

Addressing @dave changes

- Change wording when done with peer grading ("evals" -> "assessments")
- Added ICE legend item for comment syntax
- Added conditionals to display human readable 'grader_type' to alleviate confusion
- Rename 'Show/Hide Prompt' to 'Show/Hide Question'
- Reworded grading flags
- Make ICE grading container larger to more easily allow users to read and edit larger texts
- Adjusted lots of text and word choices to make them more user friendly
- Disable previous arrow on first grader feedback and next arrow on last grader feedback
- hide ORA instructions and ICE legend when calibrating so students don't feel like they need to write feedback

Changes after comments:

- Renamed instructions element and fixed casing issue
- Renamed legend class to ice-legend
- Changing condition from != to >= to not only fix incorrect one but also catch possible weirdness
- Grammar fix in a message
- Removing grader_type conditional in HTMl to give way to the one in python
- Moving ice feedback area height styling to CSS file

More changes:

- Update ICE version
- Modifying test to reflect code change
- Adding ICE undo feature

edx.org - replaces login/register semantically verbose fieldset and legend elements with simpler markup

LMS/Accounts: Converts many class-based Sass archetype-focused @extends to use Sass placeholder syntax

Verification: converts all class-based Sass archetype-focused @extends to use Sass placeholder syntax