using emalloc and efree, instead of malloc and free

renamed hostconnect() to php_hostconnect()

hostconnect now supports IPv6 if getaddrinfo exists, and also tries to
connect to all addresses of a host before giving up. It should also be
thread safe when using getaddrinfo.

Include "php.h", otherwise we don't have access to the PHP and autoconf
macros.

Added timeout argument, but not used yet

Network related functions, only for internal use by other PHP code. Tries
to hide the details of address families/protocols, and to reduce duplication
of code.