Support config from package.json and .coffeelintrc (issue #145)

Very heavily inspired by JSHint, this change will make coffeelint read config files in this order:
1) the way it is done now, if a config is provided in some way
2) from a package.json (the coffeelintConfig property) found at the location of the file being linted or some parent folder (e.g. the npm package's package.json file if working on an npm package)
2) from a .coffeelintrc file found at the location of the file being linted, or in parent folder, or in parent's parent folder, ...
3) from a .coffeelintrc file found in the user's home directory