Split `csslint` module into `csslint` and `lint` modules.
Remove file extension from `require` call.
Minor syntax improvements.
Monkey patch `csslint.CSSLint.verify` to allow linting empty files.
Separate `lint` module functions into `lintCSS` and `lintLESS`.
Renamed linter output text fixtures from `*.txt` to `*.lint`.
Tightened testing fixture regex.
Rename linter output test fixture from `*.lint` to `*.less.lint`.
Add test fixtures for linting raw CSS.
release 0.5.3