Hack an icon for name add button (#1300)

css/app.css

@@ -545,6 +545,8 @@ button[disabled] .icon.nearby     { background-position: -340px -40px;}
 .icon.out-link   { height: 14px; width: 14px; background-position: -500px 0;}
 a:hover .icon.out-link   { background-position: -500px -14px;}
 
+.icon.plus-dark    { background-position: -240px -40px;}
+
 /* Universal preset icons */
 
 .icon.source     { background-position:   0 -200px;}

js/id/ui/preset/localized.js

@@ -19,7 +19,7 @@ iD.ui.preset.localized = function(field, context) {
             .attr('class', 'localized-add')
             .on('click', addBlank)
             .append('span')
-            .attr('class', 'icon');
+            .attr('class', 'icon plus-dark');
 
         localizedInputs = selection.append('div')
             .attr('class', 'localized-wrap');