edx/edx-platform — pull request #5595 by caijim (2014-10-15 21:34:14+00:00)
Title: Support and tests for adding a reset button to units

Users may want to start anew when answering a question. This commit decouples reset from randomization while still preserving backward compatibility. Users can clear their input.
Instructors can set course-wide and problem-specific settings for reset button display.