Prevent false-highlighting-bubbling for specific occurrences within Unions

### Story ###
- https://www.pivotaltracker.com/story/show/78230864

### Notes ###
- only consider unique occurrences when building specificsRationale
- extend ```orCounts``` to consider grouping data criteria representing Unions

### Screenshots ###
- undesired false-bubbling
  - ![screen shot 2014-09-10 at 9 03 39 am](https://cloud.githubusercontent.com/assets/456952/4217738/0638fa26-38eb-11e4-93e8-68e8f08b3b3d.png)
- fixed false-bubbling
  - ![screen shot 2014-09-10 at 9 03 57 am](https://cloud.githubusercontent.com/assets/456952/4217737/063645a6-38eb-11e4-9416-e0502a8df015.png)


Code golf... is this any simpler?

    calculateDataCriteriaOrCounts: (rationale) ->
      orCounts = {}
      for key, dc of @measure.get('data_criteria') when dc.derivation_operator == 'UNION' && key.indexOf('UNION') != -1
        for child in dc.children_criteria
          orCounts[key] = (orCounts[key] || 0) + 1 if rationale[key]
      orCounts