Watching works only with --poll in docker

[wclr]

Watching works only with --poll in docker, so maybe it is reasonable to introduce some more efficient watching in containers.

[pyrossh]

No watching works fine in my docker container. I've been using it for quite a while. I think its based on your OS. I've seem some of my colleagues who use webpack in docker containers on OSX and it polls or crashes often whereas in my linux system I've never had an issue like that.

[wclr]

Yes, I'm using docker for windows.

[pward123]

Would you consider a PR for fb-watchman support with a fallback to filewatcher if watchman is not installed?

If so, what version of node are you targeting? Package.json engines says 0.8.0, but this PR has string interpolation which wasn't available until v4