Replace jsdom with domino, removing dependency on the native contextify module.

Domino is also reported to be faster, as it doesn't contain all the sandboxing
required to evaluate <script> tags in document context (which we're not using
anyway).

Use domino for all html5 parsing.

Update DOM version check for domino.
Use domino to implement Util.serializeNode().

Change-Id: I16b5fabe9130d8722c6ac177d1fc457f84cab0c0
two optional assertions for domino correctness.

Change-Id: I2d61d37f97a031b83d93129597b11a3c4b91ccb3
Allow CORS requests so external apps (Nell's Wikipedia) can use this service.
Bind server to proper port for AppFog deployment; add 'start' command.

AppFog uses the 'start' script to figure out how to run our app.
More AppFog deployment configuration files.