tls: throw an error, not string

Reviewed-By: Fedor Indutny <fedor@indutny.com>
test: assert cluster.disconnect is async

See joyent/node#8043, test passed on v0.11 already, but this makes the
test stronger.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>
path: fix slice OOB in trim

Internal function trim(arr). 2nd parameter of slice() should be slice's
end index (not included). Because of function normalize() (called before
trim()), "start" is always zero so the bug -for now- has no effect, but
its a bug waiting to happen.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>
test: disable 0-dgram tests on darwin

fix #8023
process: improve process binding

Reviewed-By: Fedor Indutny <fedor@indutny.com>
path: isAbsolute() should always return boolean

On Windows, path.isAbsolute() returns an empty string on failed cases.
This forces the return value to always be boolean.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>
test: fix test-net-remote-address-port

Do not use first socket in second socket's connect handler. Probably a
copy/paste mistake.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>
net: don't prefer IPv4 addresses during resolution

Currently the address resolution family defaults to IPv4. Instead remove
the preference and instead resolve to a family suitable for the host.

Expose the getaddrinfo flags and allow them to be passed.

Add documentation about new flags.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>
dns: fix GetAddrInfo assert

The method GetAddrInfo() is used by more than just dns.lookup(), and in
those cases a third argument isn't passed. This caused the following
check to abort:

  assert(args[3]->IsInt32());

Fixes: 4306786 "net: don't prefer IPv4 addresses during resolution"

Signed-off-by: Trevor Norris <trev.norris@gmail.com>
fs: fs.readFile should not throw uncaughtException

Reviewed-By: Fedor Indutny <fedor@indutny.com>
tests: fix child-process-fork-dgram on SmartOS.

Increase the number of total messages so that both the child and the
master process get a chance to handle at least one of them.