os/signal: windows is supported, update docs

[gopherbot]

by czapkofan:

Before filing a bug, please check whether it has been fixed since the
latest release. Search the issue tracker and check that you're running the
latest version of Go:

The issue seems to be present both in go1.0.3, and in "current tip".
http://code.google.com/p/go/source/browse/src/pkg/os/signal/signal.go?name=go1.0.3
http://code.google.com/p/go/source/browse/src/pkg/os/signal/signal.go


Which operating system are you using?
Windows


Please provide any additional information below.

The doc for os/signal package states: "BUG(rsc): This package is not yet
implemented on Plan 9 and Windows."
But it actually does seem to work, and at least one report of it "not working as
desired" was retracted as "working ok":
https://golang.org/issue/4347

So, I believe this may be a bug in current docs. If not, then could this be possibly
fleshed in some more detail in the docs? What are the problems with this feature on
Windows, and is using it considered "risky/unsupported/undocumented feature"?

[minux]

Comment 1:

https://golang.org/cl/7519045

Labels changed: added priority-soon, go1.1, removed priority-triage.

Owner changed to @minux.

Status changed to Started.

[minux]

Comment 2:

This issue was closed by revision 07fb6fc.

Status changed to Fixed.