Notecard archives

Users can archive notecards based on the date of them being written, and also edit and update them.
![selection_037](https://cloud.githubusercontent.com/assets/8248100/5345130/443a9a80-7ee3-11e4-95f7-0834a032a21e.png)
![selection_038](https://cloud.githubusercontent.com/assets/8248100/5345141/5b27d71c-7ee3-11e4-9eab-92af9b3b182d.png)
![selection_039](https://cloud.githubusercontent.com/assets/8248100/5345154/6fb2ff54-7ee3-11e4-92ad-5aaa01488107.png)


Can you run `bundle install` since rdiscount is still in the Gemfile.lock?