Data formatting and updating

[ericsvendsen]

Modified input data to accept either an object or an array (for data ordering); added the ability to pass in updated data to avoid the need to destroy/recreate the chart when the data source(s) change.

My use case is to use the radial chart to display data from multiple user-selectable data sources. When one source was added or removed, the chart's axis would not update. Also, I'm using this to display time-based data, so the order in which the bars appear is important. Therefore I modified the code to accept an array to enable sorting.