Use Raleway font for headings

gui/index.html

@@ -15,12 +15,17 @@
 
   <title>Syncthing | {{thisNodeName()}}</title>
   <link href="bootstrap/css/bootstrap.min.css" rel="stylesheet">
+  <link href="raleway.css" rel="stylesheet">
   <style type="text/css">
     body {
       padding-bottom: 70px;
       font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
     }
 
+    h1, h2, h3, h4, h5 {
+      font-family: "Raleway", "Helvetica Neue", Helvetica, Arial, sans-serif;
+    }
+
     ul+h5 {
       margin-top: 1.5em;
     }

gui/raleway.css

@@ -0,0 +1,12 @@
+@font-face {
+  font-family: 'Raleway';
+  font-style: normal;
+  font-weight: 400;
+  src: local('Raleway'), url(raleway-400.ttf) format('truetype');
+}
+@font-face {
+  font-family: 'Raleway';
+  font-style: normal;
+  font-weight: 700;
+  src: local('Raleway Bold'), local('Raleway-Bold'), url(raleway-700.ttf) format('truetype');
+}