Trebuchet enhancements

[barrybecker4]

Goal: optimize the structure in the simulation, the build physical lego trebuchet based on it.

• draw the trebuchet offset from the bottom, not the top - so we can see the arc of the projectile better (done)
• draw a trail for the arc of the projectile - to see it better (done)
• separate model from renderers (done)
• zoom out when firing so that the whole arc can be seen (done)
• the projectile should land/stop when it hits the ground (done)
• add dynamic options for things like numStepsPerFrame and all the sizes and ratios (things currently in options)
• measure the distance that it traveled and display it. This will be used to measure the fitness when optimizing (done)
• apply the optimize library to iteratively optimize a solution
• print the optimized params
• build Lego structure based on the result