Make svg elements responsive about dimple

[johnkiernander]

I've added the functionality for dynamic and resizing charts with % specifiers in any positioning attributes now supported.

[vickyonit]

@johnkiernander can you post a code snippet of using % for mentioning size for the charts!

[johnkiernander]

This example: http://dimplejs.org/advanced_examples_viewer.html?id=advanced_responsive_sizing uses fixed margins with a 100% svg. If you want to make the margins/bounds themselves scale you can set them as:

myChart.setBounds("10%", "10%", "80%", "80%");

or

myChart.setMargins("10%", "10%", "10%", "10%");

These both give identical results and will leave a 10% margin around the chart. Generally I find the fixed margin approach in the example works better though.

[vickyonit]

@johnkiernander Thank you!