function _isPointInArea(point, area, margin) {
    margin = margin || 0.5; // margin - default is to match rounded decimals
    return !area || point && point.x > area.left - margin && point.x < area.right + margin && point.y > area.top - margin && point.y < area.bottom + margin;
}
Returns true if the point is inside the rectangle
@param point - The point to test
@param area - The rectangle
@param margin - allowed margin
@private