Merge pull request #2401 from y-asaba/flot_borderwidth_fix

flot: fixed type for gridOptions.borderWidth

flot/jquery.flot.d.ts

@@ -46,7 +46,7 @@ declare module jquery.flot {
         labelMargin?: number;
         axisMargin?: number;
         markings?: any;             //array of markings or (fn: axes -> array of markings)
-        borderWidth: number;
+        borderWidth?: any;          // number or width object
         borderColor?: any;          // color or null
         minBorderMargin?: number;       // or null
         clickable?: boolean;