Added the "targets" and "trails" custom stages. They can be activated from the stages menu.
Targets is intended to test projectile-launching creations:

Trails is intended to test vehicle creations:

This update also includes the following:
- A new blueprint, "cannon", which is a reliable projectile launcher.
- Increased max speeds for pistons and motors
- Scrolling lists using thumbstick / trackpad on controllers.
