svg pan zoom.js

使用示例： svgPanZoom('#demo-tiger', { viewportSelector: '.svg-pan-zoom_viewport' , panEnabled: true , controlIconsEnabled: false , zoomEnabled: true , dblClickZoomEnabled: true , mouseWheelZoomEnabled: true , preventMouseEventsDefault: true , zoomScaleSensitivity: 0.2 , minZoom: 0.5 , maxZoom: 10 , fi