Fix Win32 socket functions
Add very rudimentary error code handling for SSL
FIX/Win32: properly munge amqp_socket_init

Properly munge the error code from amqp_socket_init on Win32, previously
it was not munged correctly and an error code could be mistaken as a
sockfd
FIX: handle getaddrinfo err codes correctly

getaddrinfo codes are a distinct enumeration from the other socket error
codes on non-Win32 systems. Use the gai_stringerr() function to generate
error codes.
amqp_socket_open() error handling fixes