Update 0.2

Update 0.2 is out. 

0.2:

• Certain model parameters are now exposed to user.  More on the way.
• Improved airplane flight model.
• VR controller axes are mapped to squares to "emulate" an RC transmitter.
• Crashing against ground is now supported.
• A "beam" from aircraft to ground is visible when close to ground (only if crashing is enabled)