Render answer form in individual question view

* Change answer symbol to object in controller and form view
* Add text to form submit button
* Fix path prefix for link to /answers/new
* Request js response after answer submission
Render answer form div on question page

* HTML form rendered on single question view
* Hide form div on page load
* Display answer form when user clicks 'add answer'
User can post answer to question

* Display answer form when user clicks button
* Associate answer with question
* Render answer ajax-ically in answer list
Merge pull request #12 from wh1tney/answers

Answers