Add information to quests on the Market before you buy them

Add popover quest description to quests in the Market and add buyQuest modal to show text and rewards before purchasing the quest.

This was suggested by Ryan on [this trello card](https://trello.com/c/XzWhIu3S/349-add-quests-ideas-here) and I thought I could handle it. I don't know if it's the best approach but it's working. It can help users see what the quest it like before they purchase it.

The picture is the modal when you click on the quest.

![buyquest1](https://f.cloud.github.com/assets/6205335/1987514/dd07c000-845a-11e3-81a1-3884b72eb2f8.png)