Include leaflet-specific class in all leafletfix selectors (#859)

Author: gadenbuie

inst/htmlwidgets/lib/leafletfix/leafletfix.css

@@ -5,25 +5,25 @@ img.leaflet-tile {
   border-radius: 0;
   border: none;
 }
-.info {
+.leaflet .info {
   padding: 6px 8px;
   font: 14px/16px Arial, Helvetica, sans-serif;
   background: white;
   background: rgba(255,255,255,0.8);
   box-shadow: 0 0 15px rgba(0,0,0,0.2);
   border-radius: 5px;
 }
-.legend {
+.leaflet .legend {
   line-height: 18px;
   color: #555;
 }
-.legend svg text {
+.leaflet .legend svg text {
   fill: #555;
 }
-.legend svg line {
+.leaflet .legend svg line {
   stroke: #555;
 }
-.legend i {
+.leaflet .legend i {
   width: 18px;
   height: 18px;
   margin-right: 4px;