Highcharts 调整曲线图的粗细、点大小、点形状

转自http://blog.youkuaiyun.com/linminqin/article/details/6995725

粗细：lineWidth  默认值为2

plotOptions: {
                    series: {
                        marker: {
                            radius: 3,  //曲线点半径，默认是4
                            symbol: 'diamond' //曲线点类型："circle", "square", "diamond", "triangle","triangle-down"，默认是"circle"
                        }
                    }
                },