use relative links instead of absolute to allow subpath installation

server.js

@@ -66,19 +66,23 @@ router.get("/", function (req, res) {
 })
 
 router.get("/demo", function (req, res) {
+  url = req.header("host") + req.baseUrl
   res.render("index.jade", {
     pageTitle: "Post-it - demo",
 	headerBarUrl: headerBarUrl,
     logoUrl: logoUrl,
+    url: url,
     demo: true
   })
 })
 
 router.get("/:id", function (req, res) {
+  url = req.header("host") + req.baseUrl
   res.render("index.jade", {
     pageTitle: "Post-it - " + req.params.id,
 	headerBarUrl: headerBarUrl,
-    logoUrl: logoUrl
+    logoUrl: logoUrl,
+    url: url
   })
 })
 

views/layout.jade

@@ -35,11 +35,11 @@ html(lang="fr")
 		div#header-bar(data-url=locals.headerBarUrl)
 		header.container.main-header
 			div.title
-				a(href="/", title="Retour à la page d'accueil")
+				a(href="//" + locals.url, title="Retour à la page d'accueil")
 					if locals.logoUrl
 						img.logo(src=locals.logoUrl, alt="logo Post-it")
 					else
-						img.logo(src="/images/logo-Post-it.svg", alt="logo Post-it")
+						img.logo(src="images/logo-Post-it.svg", alt="logo Post-it")
 				div.base-line Organiser ses idées collectivement
 			block header
 		main