Course images

Added {COURSE_STATIC_URL} format key for about section html. Changed get_about_section to be get_course_about_section in courseware.courses.

Add some more info the the "About" Course page "at a glance" section

Multicourse countries and other demographics

* Changed from 'male', 'female', and 'other' to 'm', 'f', and 'o'

Display registered when already registered for a course.

The about image is now pulled from the course data directory and shown on the homepage, about course, and dashboard. Working on a way to show other, arbitrary course images.

Force dataType to 'text json'

Ignore registrations for Courses that can't be found

Dormsbee/course images

Fix sign up styles.