[BUGFIXES]

• Test multiple possibnle portnum->name lookups in case /etc/services
  lacks one (RT96874)
  
• Stronger kill in unit-test for cygwin (RT97773)
  
• Don't try to assert the result of getnameinfo() to match
  gethostbyaddr() or getservbyport() (RT77248)
  
• Ensure that 'socktype' hint is always passed to getaddrinfo during
  unit-testing (RT96274)
  
• Fix regexp borrowed from Regexp::Common::net (RT96274)