Bug 350737: increase padding around engines in the engine manager, r=mconnor

browser/themes/gnomestripe/browser/engineManager.css

@@ -38,5 +38,10 @@
 %endif
 
 #engineList treechildren::-moz-tree-image(engineName) {
-  -moz-margin-end: 3px;
+  -moz-margin-end: 4px;
+  -moz-margin-start: 1px;
+}
+
+#engineList treechildren::-moz-tree-row {
+  height: 20px !important;
 }