Fix a bug that kept file.exists always true

#408
v6.21.8. Bugfix. Improvement.

- v6.21.8 February 5, 2013
	- Swapped out underscore dependency for lodash
	- Underscore is no longer provided to testers
	- `File::getMeta` now alises to `File.getMeta().get` if arguments have
been supplied
	- No longer does deep clones on template data per file render (just
shallow clone now)
	- Fixed a bug that keeps `exists` attribute on `File` always `true`
		- Thanks to [Stefan](https://github.com/stegrams) for [pull request
	- Updated dependencies
		- [bal-util](https://github.com/balupton/bal-util) from ~1.16.3 to
~1.16.3
		- [watchr](https://github.com/bevry/watchr) from ~2.3.3 to ~2.3.4
			- Way better performance and reliability