Ruby

• lib/resolv.rb: fix [ruby-core:28144].
  (Resolv::DNS#make_requester): pass nameserver_port to
  UnconnectedUDP.new.
  (Resolv::DNS.bind_random_port): change the is_ipv6 argument to
  bind_host.
  (Resolv::DNS::Requester#initialize): change instance variable to
  store multiple sockets.
  (Resolv::DNS::Requester#request): pass readable sockets to
  recv_reply.
  (Resolv::DNS::Requester#close): close all sockets.
  (Resolv::DNS::Requester::UnconnectedUDP#initialize): allocate
  a socket for each address family of name servers.
  (Resolv::DNS::Requester::UnconnectedUDP#recv_reply): read from the
  passwd readable socket.
  (Resolv::DNS::Requester::UnconnectedUDP#sender): use appropriate
  socket for the target nameserver.
  (Resolv::DNS::Requester::ConnectedUDP): follow the instance variable
  change.
  (Resolv::DNS::Requester::TCP#sender): ditto.
  (Resolv::DNS::Config#nameserver_port): new method.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@26637 b2dd03c8-39d4-4d8f-98ff-823fe69b080e