add tests for svg output
differentiate the r variable that stands for radius from the r variable that stands for raphael
encapsulate all interaction with raphael.  Reuse some methods. Write tests for all svg structural elements and attributes
draw functionality broken out into methods on each class
Merge branch 'wrap_raphael_add_classes' of https://github.com/chriserin/morris.js into chriserin-wrap_raphael_add_classes

Conflicts:
	lib/morris.donut.coffee
Remove reference to old SVG file.