Copy across the specified properties of each dataset when updating the chart

[tomduncalf]

I noticed that no properties of the datasets are copied across when updating the chart from a props change - in my case, trying to show or hide a series with a checkbox.

I'm open for discussion on the best way to do this - for now I've just created a whilelist of properties to copy across (with just my use case in it :)) but maybe there is a better way... could the entire datasets property just be copied across? I wasn't sure what the reasoning behind iterating over it and copying across one by one is.

[tomduncalf]

@austinpray any thoughts on this?

[tomduncalf]

Just seen #109 which looks like a better implementation of this, closing