Add node_modules to .gitignore

I do not want to check in modules installed with npm.
Ignore 'local' directory

This directory is reserved for items that should not be checked into the
repository.
Initial middleware implementation

Supports 3 HTTP requests:

  POST /
    Requires that the POST body contains data={some text to save}
    Writes the data to the datastore and returns an 8-character hex
    key as a plain text response body.

  GET /{8-character hex key}
    Looks up the string for the specified key and 302 redirects to a
    specified URL, appending the data string as a url hash

  GET /hashes/{8-character hex key}
    Looks up the string for the specified key and returns the data
    string in the plain text response body.

Todos:

  - index.js needs some refactoring to DRY it up
  - test suite
  - demo.js needs to be converted into a proper command line tool
for running outside the context of a larger connect-based node app
(i.e. a Windows service)