StaveTie updated so that direction can be set, else falls back to normal assignement from first/last notes
StaveTie updated so that direction can be set, else falls back to normal assignement from first/last notes

Silverwolf90/vexflow,jmahmud/vexflow,Silverwolf90/vexflow,Silverwolf90/vexflow,Tails/vexflow,Huji/vexflow,aaronmars/vexflow,Tails/vexflow,aaronmars/vexflow,Huji/vexflow,Tails/vexflow,Huji/vexflow,jmahmud/vexflow,aaronmars/vexflow,jmahmud/vexflow