Include a Reveal.js distribution in static and make it default

CDN can still be used via a configuration parameter. This way, development and presentation can be done locally with no network dependency.

static/reveal-js/test/test-pdf.js

@@ -0,0 +1,12 @@
+Reveal.addEventListener( 'ready', function() {
+
+	// Only one test for now, we're mainly ensuring that there
+	// are no execution errors when running PDF mode
+
+	QUnit.test( 'Reveal.isReady', function( assert ) {
+		assert.strictEqual( Reveal.isReady(), true, 'returns true' );
+	});
+
+} );
+
+Reveal.initialize({ pdf: true });