Reveal should be an outputFormat

Now any Hugo section can be configured to generate a presentation without altering its type, and the theme is more easily copied into existing sites without conflicting with any preexisting layouts.

static/reveal/plugin/multiplex/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "reveal-js-multiplex",
+  "version": "1.0.0",
+  "description": "reveal.js multiplex server",
+  "homepage": "http://revealjs.com",
+  "scripts": {
+    "start": "node index.js"
+  },
+  "engines": {
+    "node": "~4.1.1"
+  },
+  "dependencies": {
+    "express": "~4.13.3",
+    "grunt-cli": "~0.1.13",
+    "mustache": "~2.2.1",
+    "socket.io": "~1.3.7"
+  },
+  "license": "MIT"
+}