The default speed of Happy Ghasts is too slow. Adds the "/ghastspeed" command to set the global speed of new Happy Ghasts or to set the speed of specific Happy Ghasts, which is saved across server restarts.
/ghastspeed - List current speeds
/ghastspeed global SPEED - Set blocks-per-tick speed of all new Happy Ghasts
/ghastspeed SPEED - Set blocks-per-stick speed of currently ridden Happy Ghast
