DomStringMap: Data not transmitted correctly if Array of Numbers

[flowirtz]

if data is supplied as array of numbers (see dataset in i.e. activityChart and pieChart), one must insert the following code into the component at the top:

<div style="display:none;">{{dataset}}</div>

If not, only a DomStringMap whill be returned on this.dataset.
This only applies to Arrays of Numbers, Arrays of Strings are not included.

WTF?!

TODO: find more elegant way to solve this. Maybe even file a bug with Polymer.

[flowirtz]

@MaximilianV as discussed.

[flowirtz]

@jak-ing suggested that it might be due to us using .ready instead of .attached (changed in branch activity chart afaik), worth looking into
see https://www.polymer-project.org/1.0/docs/devguide/registering-elements#lifecycle-callbacks

[MaximilianV]

did anyone tried this solution proposal?

[MaximilianV]

tried it in #45 looks good to me for line/bar-chart and datafilter.
Changed piechart in #42 and bubblechart in #44
Please try it on your own. But I had no further issues after deleting this line.