Use 'entities' package instead of using a DOM hack to decode html entities.
Remove unused imports of jquery module.
Replace jquery dependency with a minimal 'fakejquery'.

The 'fakejquery' module just defines the bits we use: $.each, $.map,
$.extend, $.isArray, $.isEmptyObject (and the internal functions required
to implement those).
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).
Allow CORS requests so external apps (Nell's Wikipedia) can use this service.