Support multiple design documents

The last argument is assumed to be the CouchDB url, as normal, but all
arguments between <command> and <url> are assumed to be couch app paths.
Merge branch 'master' of https://github.com/rmg/node.couchapp.js
Add directory config
Add directory config
Add directory config
Add directory config
Add directory config
Correct the coding style from 4 space tabs to 2 space tabs
Merge pull request #66 from philwestwell/master

Directory-based config with multiple app files, pre-processing and post-processing