Implement measures and style overrides

[markusand]

Apparently there's possible option the allow initial measures (such as padding) override on initialization.

charts/src/js/charts/BaseChart.js

Line 83 in 7adc904

setMeasures() {

Styling customization is the major flaw I see in this cute charting library. Allowing some svg parameters tune combined with some css variables override would help to overcome this limitation.

[uhrjun]

Not the highest of priorities, since this is first and foremost for internal use. There are more important issues/PRs to attend to right now. Keeping this open since it won't be hard to add.