Mission list item view update

@arthurbenemann, based on our conversation last Friday regarding the rendering for the different types of mission items, this is a preliminary work toward that goal.

@jason4short, feel free to provide feedback and/or updates. 

![mission_list_item_views_draft_1](https://cloud.githubusercontent.com/assets/914968/3017636/2eb302bc-df7c-11e3-9bdc-30d0786b0b6a.png)