Rewrite "Adapting Node" section.

- Fixes #301 by mentioning the methods vs. functions issue.
- Introduces things in a new order, which seems pedagogically better: first nfcall/nfapply, then ninvoke/npost, then denodeify/nbind, then deferred.makeNodeResolver.
- Remove stuff about streams, since as of Node.js 0.10 it should no longer be a problem.