small changes in Discover()

- Win32: log addresses found in Discover() calls
- Win32: change buffer size for gethotsname in Discover()
Just found out why this is enough http://msdn.microsoft.com/en-us/library/windows/desktop/ms738527%28v=vs.85%29.aspx :

> The maximum length, in bytes, of the string returned in the buffer pointed to by the name parameter is dependent on the namespace provider, but this string must be 256 bytes or less. So if a buffer of 256 bytes is passed in the name parameter and the namelen parameter is set to 256, the buffer size will always be adequate.