plugins: add hooks for index.html template

ref #3978

src/templates/index.html

@@ -156,7 +156,9 @@
               }
             }
         </style>
+        <% e.begin_block("indexCustomStyles"); %>
         <link href="static/skins/<%=encodeURI(settings.skinName)%>/index.css?v=<%=settings.randomVersionString%>" rel="stylesheet">
+        <% e.end_block(); %>
 
         <div id="wrapper">
         <% e.begin_block("indexWrapper"); %>
@@ -177,9 +179,12 @@
         <% e.end_block(); %>
         </div>
 
+        <% e.begin_block("indexCustomScripts"); %>
         <script src="static/skins/<%=encodeURI(settings.skinName)%>/index.js?v=<%=settings.randomVersionString%>"></script>
+        <% e.end_block(); %>
         <script>
             // @license magnet:?xt=urn:btih:8e4f440f4c65981c5bf93c76d35135ba5064d8b7&dn=apache-2.0.txt
+            <% e.begin_block("indexCustomInlineScripts"); %>
             function go2Name()
             {
                 var padname = document.getElementById("padname").value;
@@ -214,6 +219,7 @@
                 }
                 return randomstring;
             }
+            <% e.end_block(); %>
 
             // start the custom js
             if (typeof customStart == "function") customStart();