lml/ost#345: Add questions with links to exercises section.

- Add `family` scope and method to the assignment model.
- Add `_questions` partial to show the exercise questions.
- Add `show_url` param and ability to the `_question` partial.
- Add `authority?` view helper function.
- Use `authority?` view helper function.
- Fix copyrights.

TODO:

- The styles for questions are a little weird.  Leaving things
  as is to wait for the UX review.
lml/ost#346: Make feedback penalty configurable.

- Add feedback penalty field to the settings store.
- Add feedback penalty to show and edit views.
- Add JS to show / hide penalty based on feedback required.
- Add help file for @kjdav with some help text.
- Ensure score detail page does not need any updates.
lml/ost#345: Fixes from @dantemss review.

- Remove the newly introduced `family` scope in favor
  of using association accessors.
- Remove extra closing tag (typo).
lml/ost#346: Fix cosmetic issues.

- Stop getting confused between JS and CS.
- Fix copyrights on changed files.
seeds for fp contracts
skip user confirmation in development
Add memoization for the `authority?` function.

- Add dependency for the `memoist` gem.
lml/ost#347: Integrate unconfirm gem.

- Add gem dependency.
- Add configuration file for unconfirm.
- Include JS and HTML.
- Add migrations.
- Modify free response and multiple choice submissions
  to use unconfirm.
lml/ost#345: Handle JP's review comments.

- Use local variable in view/controller instead of helper.
- Separate exercise section rendering for instructor and
  student roles.
- Remove memoist gem.
- Remove url partial and inline using `exercise.url`
lml/ost#346: Fix JP's review comments.

- Use `unless` instead of `if not`
- Use floating point division.
lml/ost#347: Use git reference for unconfirm gem.
Merge pull request #349 from lakshmivyas/feature/linkqb

lml/ost#345: Add questions with links to exercises section.
Merge pull request #350 from lakshmivyas/feature/feedback-penalty

lml/ost#346: Make feedback penalty configurable.
Merge pull request #352 from lakshmivyas/feature/unconfirm

lml/ost#347: Integrate unconfirm gem.
some minor adjustments to PR 349
merged in master