added a ServoVis class that draws a servo on screen

when using the ServoVis class, initialize the object in setup() with
the x, y position of the upper left corner of where you want the servo,
then display it in the draw() loop with myServoVis.display(int servo
input stream variable)
Merge pull request #1 from lucasainsworth/Development-Branch

added a ServoVis class that draws a servo on screen