Allow measure populations to be collapsed

#### Story ####
- https://www.pivotaltracker.com/story/show/65923730

#### Notes ####
- switched <code>logicView</code> to panels with Bootstrap collapse support and integrated styling
- this does **not** use accordion-based collapsing, so individual panels can be opened/collapsed as desired

#### Screenshots ####
- default measure view, collapsed
  - ![screen shot 2014-02-19 at 12 51 28 pm](https://f.cloud.github.com/assets/456952/2209649/9b14a7e6-998e-11e3-845b-e30a47b0ccb4.png)
- measure view, expanded
  - ![screen shot 2014-02-19 at 12 51 36 pm](https://f.cloud.github.com/assets/456952/2209650/9b14ff66-998e-11e3-9bf3-3f5ab42d7fa9.png)
- measure view, expanded, rationale-highlighted
  - ![screen shot 2014-02-19 at 12 51 47 pm](https://f.cloud.github.com/assets/456952/2209648/9b1488d8-998e-11e3-8915-0e69002c44f6.png)
- patient builder view, expanded
  - ![screen shot 2014-02-19 at 12 52 05 pm](https://f.cloud.github.com/assets/456952/2209647/9b146cf4-998e-11e3-89c2-96707ad8f88e.png)