Merge pull request #300 from sveltejs/gh-293

[WIP] simplify rendering of error pages

test/app/routes/5xx.html

@@ -1,6 +0,0 @@
-<svelte:head>
-	<title>Internal server error</title>
-</svelte:head>
-
-<h1>Internal server error</h1>
-<p>{error.message}</p>

test/app/routes/_error.html

@@ -2,5 +2,5 @@
 	<title>{status}</title>
 </svelte:head>
 
-<h1>Not found</h1>
+<h1>{status}</h1>
 <p>{error.message}</p>