Cope with \r\n line endings produced by Function.prototype.toString.

This should fix some tests on non-*NIX systems (#56). It would still be
worthwhile to make line endings generated by the Printer configurable, but
that's a more ambitious undertaking.

Closes #56.
Merge pull request #59 from benjamn/issue56

Cope with \r\n line endings produced by Function.prototype.toString.