Keep the buddy list visible when you're declaring a crisis to specific buddies

https://www.pivotaltracker.com/story/show/40461093
Refactor code that shows and hides #battle-buddies-list

Removes redundant JS and style in the views in favor of stylesheet and
jS file

https://www.pivotaltracker.com/story/show/43069449 and
https://www.pivotaltracker.com/story/show/40461093