Sightglass Default Adapter Iteration

[milonas115]

Iterate the "change" callbacks backwards. Changes to the callbacks by custom binders will cause some parts of the loop to try to call an "undefined" function, or in the weird case, to skip a callback entirely.

if (weakmap[r].callbacks[k] instanceof Array)
{
	for(var i=weakmap[r].callbacks[k].length-1;i>=0;i--)
		weakmap[r].callbacks[k][i]();
}

if (callbacks[keypath])
{
	for(var i=callbacks[keypath].length-1;i>=0;i--)
		callbacks[keypath][i]();
}