* Don't try to ignore SIGPIPE in Windows (it doesn't exist).
* Add an include to our win32.h compatibility header.
* Enable building examples on Travis in Windows.
See #831
To minimize code changes, a simple `u` (or UNIX, Unix, unix, etc -- as
long as the first character is u or U) is used as a marker for the
'port' argument. In this case, the hostname is interpreted to be the
path to the unix socket.
