Cleaning up Makefile, port handling, static url refs.

1. Cleaning up Makefile;
    * removing unused tasks
    * reording so `make` alone installs npms and runs.
    * npm's are only installed if they haven't been before, to update/reinstall run `make clean node_modules`.
2. Fixing env port handling;
    * `PORT=3333 node server.js` didn't work.
3. Removing static references to `localhost:3000` for running on other ports and with a hostname.