Fix tooltip class

c3.css

@@ -90,7 +90,7 @@ text {
 
 /*-- Tooltip --*/
 
-.tooltip {
+.-tooltip {
   border-collapse:collapse;
   border-spacing:0;
   background-color:#fff;
@@ -100,28 +100,28 @@ text {
           box-shadow: 7px 7px 12px -9px rgba(119,119,119,10);
   opacity: 0.9;
 }
-.tooltip tr {
+.-tooltip tr {
   border:1px solid #CCC;
 }
-.tooltip th {
+.-tooltip th {
   background-color: #aaa;
   font-size:14px;
   padding:2px 5px;
   text-align:left;
   color:#FFF;
 }
-.tooltip td {
+.-tooltip td {
   font-size:13px;
   padding: 3px 6px;
   background-color:#fff;
   border-left:1px dotted #999;
 }
-.tooltip td > span {
+.-tooltip td > span {
   display: inline-block;
   width: 10px;
   height: 10px;
   margin-right: 6px;
 }
-.tooltip td.value{
+.-tooltip td.value{
   text-align: right;
 }

c3.js

@@ -104,7 +104,7 @@
         // tooltip - show when mouseover on each data
         var __tooltip_contents = getConfig(['tooltip','contents'], function(d) {
             var date = isTimeSeries ? d[0].x.getFullYear() + '.' + (d[0].x.getMonth()+1) + '.' + d[0].x.getDate() : isCategorized ? category(d[0].x) : d[0].x,
-                text = "<table class='tooltip'><tr><th colspan='2'>" + date + "</th></tr>", i, value, name;
+                text = "<table class='-tooltip'><tr><th colspan='2'>" + date + "</th></tr>", i, value, name;
             for (i = 0; i < d.length; i++){
                 if (isDefined(d[i])) {
                     value = isDefined(d[i].value) ? (Math.round(d[i].value*100)/100).toFixed(2) : '-';