FlightGear - Flight Simulator FGAddon

* Nasal/doors.nas (crew): rename to left_window; change property.
(passenger): rename to right_window; change property.
(crew, bombs): new.
* Models/Interior/interior.xml: animate windows with the new properties.
* Models/b25.ac (Bombsdoorleft, Bombsdoorright, Crewdoor, Ladder): new.
* Models/b25.xml (nasal/load): alias new incoming properties for bomb and
crew doors. Animate windows, bomb and crew doors.
* Models/main_Chrome.xml,
Models/main_Default.xml: delete duplicated animations of windows;
add the new objects to texture and effect animations.
* Systems/b25-keyboard.xml (d): toggle bomb bay doors like in the Mosquito.
(D): toggle crew door.
* Systems/help.xml: likewise.
* b25-base.xml (sim/multiplay): send bomb and crew door positions.