Merge branch 'master' into nixta-working

* master:
Working part-piechart
Better pie charts. Still not good though - still using two layers.
Better error handling and some more improvements to the World Bike Map (e.g. a legend).
First stab at dojo charts - rendering still a problem.
Refactoring of Citibike code. Also a bug fix for pre caching and subsequent loading of stations data (it was happening too often).
Merge branch 'svg-piecharts' into svg-piecharts-dojochart

* svg-piecharts:
  Refactoring of Citibike code. Also a bug fix for pre caching and subsequent loading of stations data (it was happening too often).
Dojo Charts used for creating the symbols.
Merge branch 'svg-piecharts-dojochart' into nixta-working

* svg-piecharts-dojochart:
  Dojo Charts used for creating the symbols.
  Refactoring of Citibike code. Also a bug fix for pre caching and subsequent loading of stations data (it was happening too often).
  First stab at dojo charts - rendering still a problem.
  Better error handling and some more improvements to the World Bike Map (e.g. a legend).
  Better pie charts. Still not good though - still using two layers.
  Working part-piechart
Merge pull request #19 from nixta/nixta-working

Refactoring and Dojo Charts for the Bikeshare symbols.