Added comments for the smoothVar if statements

In tankdrive smoothVarRight and smoothVarLeft were switched because in the output they were switched (the right joystick made smoothVarLeft change and the left joystick made smoothVarRight change). Testing the robot gave some strange values for smoothVarRight. First off, values were switched (joystick going forward gave a negative value), and the values were way off from what they're supposed to be (-3.6...etc). We should probably look at the equation (although graphing the equation shows that it's correct, yet the code is way off). Also, the "smoothness" only works when you push the joysticks backward (values are positive as stated above) but not forward.