Feature request: Reverse symlink lookup

[e2]

Currently, Listen follows directory symlinks to watch the "real" directories.

This feature would enable listen to report changes as if it the symlinked directories were real directories.

e.g. given the directories and symlinks:

mkdir foo
ln -s foo bar  # bar -> foo
ln -s foo baz  # baz -> foo

When watching simultaneously foo and bar and baz, a change in any of those should result in changes reported in all 3 "directories" (even though it physically happens only in foo).

This would allow apps such as Guard to "watch" bar and receive events relative to bar so symlinked directories would be "transparent" (regardless of how the backend treats them).

E.g. if baz is watched, and foo/file.txt changes, then Listen should only report baz/file.txt as changed.

How to implement

Just as Listen has a record of files and their attributes, it would need a record of symlinks relative to which it could "generate" the events (based on the real event).

Current behavior

This is "partially implemented" (incorrectly), by reporting files as relative to the watched directory, which means potentially reporting non-existing paths as changed (test cases are needed).

Pitfalls

This could obviously be slow in some scenarios, e.g. an :absolute_events option could skip this resolution.