Use svg favicon

Author: ahornace

opengrok-web/src/main/webapp/default/img/apple-touch-icon.png

@@ -0,0 +1,11 @@
+{
+  "name": "OpenGrok - a wicked fast source browser",
+  "short_name": "OpenGrok",
+  "icons": [{
+    "src": "./img/google-touch-icon.png",
+    "sizes": "512x512"
+  }],
+  "background_color": "#ffffff",
+  "theme_color": "#ffffff",
+  "display": "fullscreen"
+}

opengrok-web/src/main/webapp/default/img/favicon.svg

@@ -56,7 +56,11 @@ org.opengrok.web.Scripts"
 <meta name="robots" content="noindex,nofollow" />
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
 <meta name="generator" content="{OpenGrok <%=Info.getVersion()%> (<%=Info.getRevision()%>)" />
-<link rel="icon" href="<%=styleDir%>/img/icon.png" type="image/png" />
+<meta name="theme-color" content="#ffffff">
+<link rel="icon" href="<%=styleDir%>/img/favicon.svg">
+<link rel="mask-icon" href="<%=styleDir%>/img/mask-icon.svg" color="#000000">
+<link rel="apple-touch-icon" href="<%=styleDir%>/img/apple-touch-icon.png">
+<link rel="manifest" href="<%=styleDir%>/manifest.json">
 <link rel="stylesheet" type="text/css" media="all"
     title="Default" href="<%= dstyle %>" />
 <link rel="alternate stylesheet" type="text/css" media="all"