jmoiron plays the blues

Argent-Matter/gcyr 1.20.1 8204737 use MOTION_BLOCKING_NO_LEAVES to ignore leaves when determining the landing surface distance when landing/falling
Argent-Matter/gcyr 1.20.1 654380c rename countdown() to countdownComplete() so its boolean value is easier to understand at the call site, introduce a COUNTDOWN_TICKS constant as we are using that magic value in quite a few locations
Argent-Matter/gcyr 1.20.1 a2706b8 style odds and ends, refactor addBlock to remove all quadratic behavior, add finalizer that calculates everything and sets entity data once, fix res loc for destination planet