changed combo detector, added state memory, throwing issue, catching countdown

combodec: better compliance with LF2

statemem: statemem is managed by livingobject.js, and is cleared automatically every state transition

throwing issue: `Throwing anything in LF2 (character/item) does not only happen while holding left/right and pressing attack but also when holding up/down and pressing attack.` on https://github.com/tyt2y3/F.LF/issues/8

countdown: see frame transition sequence for details
Merge branch 'master' of https://github.com/tyt2y3/F.LF