Fix some typoed names from the doc
Add _index to "index" parameters of *_shape_* signals, this is both in doc and in the template. This makes the code, signature and doc easier to understand
Add method to get Node from the _index params of those signals. This was not as easy to find as one would expect. Putting this information where it is needed will help.
RigidDynamicBody modes are replaced with several properties to make their
usage clearer:
-lock_rotation: disable body's rotation (instead of MODE_LOCKED)
-freeze: no gravity or forces (instead of MODE_STATIC and MODE_KINEMATIC)
-freeze_mode: Static (can be only teleported) or Kinematic (can be animated)
Also renamed MODE_DYNAMIC_LOCKED to MODE_DYNAMIC_LINEAR in the physics
servers.
