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
- if measure visualization has an error, an error message is printed instead
- functional for single and multiple populations across measures not listed below
- measures with **errors** (measure_id [population title]):
  - "0075 [Most Recent LDL-C <100 mg/dL]"
  - "0075"
  - "CholesterolScreeningRisk [LDL-C <130 mg/dL]"
  - "CholesterolScreeningRisk [LDL-C <160 mg/dL]"
  - "CholesterolScreeningRisk"
  - "FastingLDLTest [Moderate Risk]"
  - "FastingLDLTest [Low Risk]"
  - "FastingLDLTest"
  - "0421 [65+]"
  - "0421 [18-64]"
  - "0421"
  - "BPScreen"
  - "HypertensionImprovement"
  - "0405 [At Diagnosis of HIV]"
  - "FSACHF"
  - "0418"
  - "ADE_TTR"
  - "HIVRNAControl"
  - "0608"
  - "0070 [LVSD]"
  - "0070 [prior MI]"
  - "0070"
  - "0385"
  - "0387"
  - "0031"
  - "0032"
  - "0083"
  - "0389"
  - "0052"
  - "0081"
  - "0059"
  - "0064"
  - "0033 [16-24]"
  - "0033 [RS1: 16-20]"
  - "0033 [RS2: 21-24]"
  - "0033"
  - "0028"
  - "0004 [Treatment]"
  - "0004 [Treatment w/ AOD]"
  - "0004 [Treatment, RS1: 13-17]"
  - "0004 [Treatment, RS2: >=18]"
  - "0004 [Treatment w/ AOD, RS1: 13-17]"
  - "0004 [Treatment w AOD, RS2: >=18]"
  - "0004"
  - "0041"
length: 45

#### Screenshots ####
- measure view without viz toggle
  - ![screen shot 2014-02-27 at 2 23 06 pm](https://f.cloud.github.com/assets/456952/2286795/93b8c9d4-9fe5-11e3-81de-83259393a40a.png)
- measure view with viz toggle
  - ![screen shot 2014-02-27 at 2 23 13 pm](https://f.cloud.github.com/assets/456952/2286796/93bbd660-9fe5-11e3-9858-68f88b0d7b0d.png)