Canvasfill

This branch adds the Fill property to the AI2 Canvas. This allows for the drawing of unfilled circles (eliminating the need to implement DrawRing) and text (allowing users to draw unfilled block letters). It also allows for future implementation of DrawRectangle, DrawOval, DrawPath, and other shapes without having to implement both filled and unfilled versions.

A test app can be found <a href="http://people.cs.clemson.edu/~mdabney/AppInventor/FillTest.aia">here</a>.