Migrate to snowfall lib

modules/home/gui/apps/firefox/userChrome.css

@@ -0,0 +1,14 @@
+#main-window[tabsintitlebar="true"]:not([extradragspace="true"]) #TabsToolbar > .toolbar-items {
+    opacity: 0;
+    pointer-events: none;
+}
+#main-window:not([tabsintitlebar="true"]) #TabsToolbar {
+    visibility: collapse !important;
+}
+#sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"] #sidebar-header {
+    display: none;
+}
+.tab {
+    margin-left: 1px;
+    margin-right: 1px;
+}