Tidy AutoTarget code.
Remove redundant AttackMove definitions.
Add AttackMove support to RA aircraft.
Simplify HeliFly interface.
Add range support to HeliFly.
Simplify Fly interface.
Add range support to Fly.
Ensure that planes circle after being ordered via IMove.
Add following to IMove.
Add Guard support to Aircraft.
Fix HeliFly lua bindings.
Make aircraft guardable.
Merge pull request #4478 from pchote/aircraft-follow

Add Guard and AttackMove to RA and C&C aircraft.