F4U: add checklists, allow-toggle-cockpit, add key binding to toggle auto-coordination
This helps beginners take off with this difficult (as in real life) aircraft.
README: delete the documentation about key bindings, it was redundant with the one in f4u-set.xml and incorrect.
Authored by: lbrenta 2015-11-19
Parent: [r1108]
Child: [r1110]
