fix helper comment and enhance test readme w/ links
There are now draw, move, and setColor tests for polygons. Still need to do reflection tests for polygons.
Sketches now use d3 formatting to round the elements of point strings for polygons.
Added comment about tests. Occasional unexpected test failure, most likely caused by d3 transitions overriding each other. Please read if it occurs.
unit test the radiogroup widget
skip the radio group tests for the method that hasn't been written
Merge pull request #40 from mlippert/widget-refactor

radio group unit tests
Merge branch 'upstream/master'