simplebalac fully functional with 1 speed

created threshold tilt to move ball - ball currently moves at 5 hertz.
X/Y ball coordinate on digit 0 and 1 of sevensegment display - digits
7:2 display accelerometer data.
added multiple speeds to ball
added more speed grades to the ball

see file 'fastball.v'
fixed typos
ball with compatible port map

Under the 'ball ' file there is a new folder called formated_ball which
should write out movement pulses on an output wire with the following
signals:
move_pulses[3:0] {x_increment, x_decrement, y_increment, y_decrement}
added a smoothly updating ball

I have added a ball which updates position smoothly based on acc
reading. It doesnt quite work yet, I think for signals that are
functions you have to use wires and I am using a reg. But ill fix it
after some sleep.
Merge pull request #3 from 540-Final/accel_ball_interface

Accel ball interface