Update version to 2.0.4

Replace threat handler file with named pipe

This was causing problems in MacOS for some reason. The named pipe is
probably a better solution in general, but it's strange that it happened
at all.

Add file tester

Should be useful for onboarding to package managers. Does non-trivial
testing on the files, but doesn't actually launch fzf.

Move sleep from INFINITY to 99999

Mac doesn't like infinity...

Merge pull request #11 from google/code-restructure

Code restructure