Toggle measure visualization in measure view

#### Story ####
- https://www.pivotaltracker.com/story/show/65020512

#### Notes ####
- added button to Measure settings button group for toggling measure visualization
- added fix for height within each patient population
- updated styling to reflect overall patients coverage in visualization

#### Screenshots ####
- measure view without viz toggle
  - ![screen shot 2014-03-17 at 1 22 09 pm](https://f.cloud.github.com/assets/456952/2439087/78398f96-adf9-11e3-927e-f6fd955d735f.png)
- measure view with viz toggle
  - ![screen shot 2014-03-17 at 1 22 17 pm](https://f.cloud.github.com/assets/456952/2439086/7838b31e-adf9-11e3-9760-0821d6068344.png)