Improve feature list performance

css/app.css

@@ -737,20 +737,15 @@ a:hover .icon.out-link   { background-position: -500px -14px;}
     border-bottom: 1px solid #ccc;
 }
 
-.feature-list-button-wrap {
-    position: relative;
-    margin-bottom: 10px;
-    height: 60px;
-}
-
-.feature-list-button {
+.feature-list-item {
     width: 100%;
-    height: 100%;
+    height: 60px;
+    margin-bottom: 10px;
     position: relative;
     border: 1px solid #ccc;
 }
 
-.feature-list-button .label {
+.feature-list-item .label {
     background-color: #f6f6f6;
     text-align: left;
     position: absolute;
@@ -770,11 +765,11 @@ a:hover .icon.out-link   { background-position: -500px -14px;}
     border-radius: 0 3px 3px 0;
 }
 
-.feature-list-button:hover .label {
+.feature-list-item:hover .label {
     background-color: #ececec;
 }
 
-.feature-list-button .entity-name {
+.feature-list-item .entity-name {
     font-weight: normal;
     padding-left: 10px;
 }

js/id/ui/feature_list.js

@@ -73,21 +73,16 @@ iD.ui.FeatureList = function(context) {
             var items = list.selectAll('.feature-list-item')
                 .data(features(), function(d) { return d.entity.id; });
 
-            var enter = items.enter().append('div')
-                .attr('class', 'feature-list-item');
-
-            var wrap = enter.append('div')
-                .attr('class', 'feature-list-button-wrap col12');
-
-            var label = wrap.append('button')
-                .attr('class', 'feature-list-button')
+            var enter = items.enter().append('button')
+                .attr('class', 'feature-list-item')
                 .call(iD.ui.PresetIcon()
                     .geometry(function(d) { return d.geometry })
                     .preset(function(d) { return d.preset; }))
                 .on('mouseover', function(d) { mouseover(d.entity); })
                 .on('mouseout', function(d) { mouseout(); })
-                .on('click', function(d) { click(d.entity); })
-                .append('div')
+                .on('click', function(d) { click(d.entity); });
+
+            var label = enter.append('div')
                 .attr('class', 'label');
 
             label.append('span')