Two-step delete (part 1) for Measure view

**Story: (ongoing)** https://www.pivotaltracker.com/story/show/62487888

- Added popover closing functionality on click anywhere but specific popover content or gear icon **(needs review)**
- Updated styling to match v5 mockup

If this is too early to review, please feel free to close this request until I can get to other two-step delete for the story (editable data criteria in the Patient Builder view).

![popover_closed](https://f.cloud.github.com/assets/456952/1872523/7d3b29c8-78a7-11e3-8810-fad57060e719.png)
![popover_opened](https://f.cloud.github.com/assets/456952/1872524/7f285332-78a7-11e3-8ab7-47c25e5f81a1.png)
![popover_delete](https://f.cloud.github.com/assets/456952/1872525/80883918-78a7-11e3-87be-7df9b95d739c.png)