Add base.css for basic non-converse specific styles

base.css

@@ -0,0 +1,4 @@
+body {
+    font: 100% Arial, FreeSans, sans-serif;
+    font-family: "Helvetica Neue", Arial, FreeSans, sans-serif;
+}

index.html

@@ -4,6 +4,7 @@
         <title>Converse.js Demo Page</title>
         <!-- This is a special version of jQuery with RequireJS built-in -->
         <link rel="stylesheet" href="Libraries/css/jquery-ui-1.9.1.custom/ui-lightness/jquery-ui-1.9.1.custom.css" type="text/css" media="all">
+        <link rel="stylesheet" href="base.css" type="text/css" media="all">
         <link rel="stylesheet" href="converse.css" type="text/css" media="all">
         <script data-main="main" src="Libraries/require-jquery.js"></script>
     </head>