add icons for new zones

hobo/static/css/style.css

@@ -1,6 +1,15 @@
 li.zone-settings a { background-image: url(../img/icon-settings.png); }
 li.zone-settings a:hover { background-image: url(../img/icon-settings-hover.png); }
 
+li.zone-users a { background-image: url(../img/icon-users.png); }
+li.zone-users a:hover { background-image: url(../img/icon-users-hover.png); }
+
+li.zone-roles a { background-image: url(../img/icon-roles.png); }
+li.zone-roles a:hover { background-image: url(../img/icon-roles-hover.png); }
+
+li.zone-webforms a { background-image: url(../img/icon-webforms.png); }
+li.zone-webforms a:hover { background-image: url(../img/icon-webforms-hover.png); }
+
 p.being-deployed {
   background: url(indicator.gif) no-repeat;
   padding-left: 2em;