On branch master
 yeah there are a lot of logical paths in this function

	modified:   board.js
 On branch master
 added emanateKill to the callback, so pieces captured on slide don't disappear
 before the piece arrives.
	modified:   board.js
 On branch master
getEmptyGroup exists but does not fully recurse yet
	modified:   board.js
 On branch master
GetEmptyGroup() appears to work, not tested.

	modified:   board.js