Adds legends
Adjusts style
Stacked legends
Adds comment explaining how to use stacklegends
Removes the model requirement. Fixes specs.
Adds more specs
Updates style of the legends
added legends to visualization
Shows null value
Merge branch 'feature/legends' of github.com:CartoDB/cartodb.js into feature/legends

* 'feature/legends' of github.com:CartoDB/cartodb.js:
  added legends to visualization
Adds more legends
Adds intensity color generation
Style fix
Bubbles style
Density
added legend options
Refactors some code
Removed unused style
Merge branch 'feature/legends' of github.com:CartoDB/cartodb.js into feature/legends

* 'feature/legends' of github.com:CartoDB/cartodb.js:
  added legend options
Merge branch 'feature/legends' into develop

* feature/legends:
  Removed unused style
  Refactors some code
  added legend options
  Density
  Bubbles style
  Style fix
  Adds intensity color generation
  Adds more legends
  Shows null value
  added legends to visualization
  Updates style of the legends
  Adds more specs
  Removes the model requirement. Fixes specs.
  Adds comment explaining how to use stacklegends
  Stacked legends
  Adjusts style
  Adds legends