Update README.md

Add keyword "lint" to readme for SEO.
Update README.md and add hasOnly condition

Various other fixes also included here, mostly related to hasOnly.
Search for .swifferrc files

Each file may use a different set of rules, depending on the directory. It may be eventually be a good idea to cache these rules per directory, if this turns out to be a performance problem.
Add support for partials and bodies

Also, fix a scoping error in bin/swiffer
Add LICENSE and update package.json for npm
Add npm install reference to README
Add LICENSE, allow recursion, add %

Fixes #10
Merge branch 'master' of github.com:smfoote/Swiffer.js
Merge package.json
Removed unused variables from check function