Set up JSHint and pass it

Violations:
* 'prepared' is defined but never used.
* 'Tokenizer' is not defined.
* 'token' is defined but never used.

Changes:
* Updating coding style and documentation.
* Made Tokenizer not a global variable but a local function, like CSSJanus.
* Swapped Tokenizer and CSSJanus to make it clearly defined
  before the first reference to it appears.

Fixes #14