Support Axis formating/customization

[dyorgio]

Include on Ticks config the userCallback property:

http://stackoverflow.com/questions/36918887/chart-js-2-0-formatting-y-axis-with-currency-and-thousands-separator

Example:

https://jsfiddle.net/4sLxyfya/7/

[kegoe]

@dyorgio , @moberwasserlechner, is any of you working on a solution for this or on related #40? We currently consider implementing this, so any update would be appreciated.

[dyorgio]

Hi @kegoe, sadly I'm working with a private fork of this repo.
I would like to return to use this codebase as binary dependency only in the future, but I need the support to pass function to chartjs.

[kegoe]

#87 solves this while keeping the elemental.json code

[dyorgio]

Very nice solution @kegoe, transfer js functions as String and parsing it on js callback code was my initial idea, but for some reason I gave up to do this. I'm sure that this is a very much elegant solution 🤓