auto restore last attempt training

![screen shot 2014-09-07 at 22 55 35](https://cloud.githubusercontent.com/assets/4983239/4178625/2f710756-369f-11e4-837b-8bb14d17017b.png)

1. If a student haven't done a coding question, his code will be saved and auto restore next time.

2.provide a button if he wants to revert to the template code

3.UI is not beautiful.. need improve
This is a good idea.

On Tue, Sep 9, 2014 at 10:54 PM, Raymoond Tang <notifications@github.com>
wrote:

> In app/views/assessment/training_submissions/_do_coding.html.erb:
>
> >  </div>
> > +
> > +<% if last_attempt && !finished %>
> > +    <div class="btn btn-warning btn-small" id="revert-button" style="margin-top: 5px">We have restored your previous code, click to revert</div>
> > +<% end %>
>
> I guess it's better to provide a toggle button, maybe the student want to
> see the template, then restore his previous code ?
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/Coursemology/coursemology.org/pull/203/files#r17305231>
> .
>