Update scale of ruler and amplitude units

[arouinfar]

The scale of the rulers in the HTML5 version of WOAS is a bit unrealistic. The rulers are currently 5 cm and 10 cm. If we change the amplitude to be measured in meters, we can simply add zeros to the end of all of the numbers on the ruler and the scale will be more appropriate. We should address this issue in the next version of the sim.

For comparison, the rulers on the Flash version are 50 cm and 100 cm.