cluster: report more errors to workers

Some errors for listening and binding to a socket were not properly
delivered to workers.

fix #6767
test: fix test-cluster-eaccess to work on windows
docs: process.on('exit') receives exit code

The fact that the "exit" event passes the exit code as an argument
as omitted from the documentation. This adds the explanation and
augments the example code to show that.
doc: clarify process on exit safe usage
doc: document that `process.send` is synchronous

Ref #2598
blog: Post for v0.11.10
Merge remote-tracking branch 'upstream/v0.10' into v0.10