Support Svelte 3

fixes #546, #551, #552, #554

runtime/src/app/goto/index.ts

@@ -0,0 +1,13 @@
+import { history, select_target, navigate, cid } from '../app';
+
+export default function goto(href: string, opts = { replaceState: false }) {
+	const target = select_target(new URL(href, document.baseURI));
+
+	if (target) {
+		history[opts.replaceState ? 'replaceState' : 'pushState']({ id: cid }, '', href);
+		return navigate(target, null).then(() => {});
+	}
+
+	location.href = href;
+	return new Promise(f => {}); // never resolves
+}