update list of published files in package.json

- this will fix a problem with npm (potentially) publishing certain files
which should always be ignored; see npm/npm-packlist#14.
- also fixes issue with growl images not getting published!
- add `directories` property for metadata

PRO TIP: use `npm pack --dry-run` to see what would be included in
published tarball.

package.json

@@ -510,14 +510,20 @@
     "watchify": "^3.7.0"
   },
   "files": [
-    "bin",
-    "images",
-    "lib",
+    "bin/{*mocha,options.js}",
+    "assets/growl/*.png",
+    "lib/**/*.{js,html}",
     "index.js",
     "mocha.css",
     "mocha.js",
     "browser-entry.js"
   ],
+  "directories": {
+    "doc": "doc",
+    "bin": "bin",
+    "lib": "lib",
+    "test": "test"
+  },
   "browser": {
     "growl": "./lib/browser/growl.js",
     "tty": "./lib/browser/tty.js",