Added much better error checking to make first-time config easier

this includes:
* Checking collider shape/size matches character controller
* checking flight controller is present
* Checking Character controller is present
* Checking that a single collider is present

Also, the drop down menus now show up a little more intuitively.
Fixed bug in flight camera

* If script wasn't attached directly to the target, camera rotations would not take place
Also: Added better init config. There is a good chance the script will be zero-config
if the scene has been setup properly.