serve: Make the server find assets generated by external tools. When a processor is bypassing PieCrust's pipeline, we don't know what output files they have produced, so if we don't find an asset in the record for a given path, we quickly check the output folder for any matching file there. If there is, just return it.

[pytest]
norecursedirs = .* _darcs CVS .svn .git .hg *.egg-info dist build node_modules venv tmp* {args}