Merge pull request #7 from caitp/pass-options-to-compiler

Pass 'bare' option to coffee-script.compile()
Fixes #8 - Make base64 encoding of src optional

- Added new boolean option `encodeSrc`
- Conditionally encode and append coffee source file depending on
  value of `options.encodeSrc`
- Updated README.md and middleware.js comments to reflect this
  behaviour.