Control-line simulation in PicaSim

More progress with control-line simulation. Now the line simulation itself is much better, including collisions with the ground and wind resistance (which affects the plane too). You can also configure the launch setup so that you're not constrained to the centre of the circle. There are two planes I've been setting up - a variant of the Extra that's already in the simulator, which is quite slow and good for precision aerobatics (and learning I guess). The second model is smaller and faster aerobatic/combat plane called the Peacemaker.