Issue #10. Experimental version with parameterization.
Moves Box back into Result to be a single file module.
Go back to flatMap rather than "then". Need to think about what to call it more.
Merge branch 'master' of https://github.com/kareman/LlamaKit into parameterize

Conflicts:
	LlamaKit/Result.swift
	LlamaKitTests/ResultTests.swift
Merge branch 'parameterize' back to 'master'.