better user icon style.

css/app.css

@@ -407,6 +407,14 @@ button[disabled] .label {
     margin-right: 3px;
 }
 
+.user-icon {
+    max-height: 20px;
+    max-width: 20px;
+    height: auto;
+    width: auto;
+    border-radius: 3px;
+}
+
 /* Definitions for every icon */
 .icon.browse     { background-position:   0px -20px;}
 .icon.add-point  { background-position: -20px -20px;}
@@ -961,11 +969,6 @@ div.typeahead a:first-child {
     right: -30px;
 }
 
-.user-icon {
-    max-width: 50px;
-    max-height: 50px;
-}
-
 .modal-section {
     padding: 20px;
 }

js/id/ui/commit.js

@@ -60,7 +60,7 @@ iD.ui.commit = function(map) {
             user_link
                 .append('img')
                     .attr('src', user.image_url)
-                    .attr('class', 'icon icon-pre-text');
+                    .attr('class', 'icon icon-pre-text user-icon');
         }
 
         // Confirm / Cancel Buttons

js/id/ui/userpanel.js

@@ -18,7 +18,7 @@ iD.ui.userpanel = function(connection) {
                     // Add thumbnail or dont
                     if (user_details.image_url) {
                         userLink.append('img')
-                            .attr('class', 'icon icon-pre-text')
+                            .attr('class', 'icon icon-pre-text user-icon')
                             .attr('src', user_details.image_url);
                     } else {
                         userLink.append('span')