Fixed x-y bug for force

Miha

2016-07-15 c372c14d1f552a3219a733394141179c9e800683

Fixed x-y bug for force

 src/energy.c

@@ -228,7 +228,7 @@
    ynorm/=norml;
    znorm/=norml;
    /*calculate ddp, perpendicular displacement*/
    ddp=xnorm*(vtx->x-vtx_old->x)+xnorm*(vtx->y-vtx_old->y)+znorm*(vtx->z-vtx_old->z);
    ddp=xnorm*(vtx->x-vtx_old->x)+ynorm*(vtx->y-vtx_old->y)+znorm*(vtx->z-vtx_old->z);
    /*calculate dE*/
//    printf("ddp=%e",ddp);
    return vesicle->tape->F*ddp;