Update the redeem code schema

Updating the redeem code schema.

Adding migration file.

Adding course mode support when redeeming a code.

Conflicts:
	lms/djangoapps/shoppingcart/views.py

Add sales admin privileges for redeem code generation.

Making sure redeem code URLs work for verified courses.

pep8 violations

Code Review and Test Cleanup changes

Added tests, fixed tests.

Updating the boolean checks in ecommerce template

Set marketing site logged in cookie from third party auth.

Make donations configurable

Added donation button to dashboard

Generalize merchant defined data for payment processor

ECOM-41

added CoursmodeArchive model to save the old prices history

analytics -> instructor_analytics

analytics -> instructor_analytics

This commit updates common/djangoapps.

These keys are now objects with a limited interface, and the particular
internal representation is managed by the data storage layer (the
modulestore).

For the LMS, there should be no outward-facing changes to the system.
The keys are, for now, a change to internal representation only. For
Studio, the new serialized form of the keys is used in urls, to allow
for further migration in the future.

Co-Author: Andy Armstrong <andya@edx.org>
Co-Author: Christina Roberts <christina@edx.org>
Co-Author: David Baumgold <db@edx.org>
Co-Author: Diana Huang <dkh@edx.org>
Co-Author: Don Mitchell <dmitchell@edx.org>
Co-Author: Julia Hansbrough <julia@edx.org>
Co-Author: Nimisha Asthagiri <nasthagiri@edx.org>
Co-Author: Sarina Canelake <sarina@edx.org>

[LMS-2370]

Added an expiration_datetime field to CourseModes, intended to eventually replace expiration_date.

Included relevant schema and data migration file.

LMS-1454

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