Add listen 2 support.

[cduez]

This solve #1.

All work was done here rails/spring#194.

We are actually using it and everything is working as expected.

[e2]

Thanks for putting this together!

There's a few issues not related to the patches themselves, but I think this can be released anyway in the meantime.

The issues:

• there's a patch for the fork() problem in Celluloid, but it never got backported
• there's an upcoming optimized version of Listen 3.0, but it's not released yet
• there's a listen-compat library, which is supposed to wrap Listen, so that any version can be used

Anyway, thanks for moving this forward!

[e2]

@cduez - spring-watcher-listen released (2.0.0) and Listen is updated (3.0.0) - together they should work faster and without issues. (Let me know if you have any).

[cduez]

Thanks for the release and the update! I will test it asap.

[pjg]

This is awesome! No, it's even beyond awesome!

(PS: quick tests show that this works as intended)

[e2]

@pjg - thank @cduez for PR.

Do report any issues you find with Listen 3.x, since it's a major, major rewrite.

[pjg]

Yes, thank you @cduez !