Closes https://github.com/MusicPlayerDaemon/MPD/issues/1115

The ones in std have overloads for const char/char.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

The former was deprecated with C++14.

According to the C++11 and C++17 standards, both files are identical.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

.. and not "UNIX domain socket.  Be consistent about the naming.

Only _WIN32 is defined by the compiler, and WIN32 is not standardized
and may be missing.

Closes #169

This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

Handles abstract sockets on Linux.

No GLib memory allocation.

No GLib memory allocation.

getnameinfo() doesn't work well - it always returns "localhost".

Replaces GLib's GError.

GLib 2.16 was released more than 4 years ago.  Let's remove some cruft
from the glib_compat.h header, and avoid new cruft to it.

In a C file, that is too late, because _mingw.h defaults to 0x0502,
and ours would be illegal redefintion.

Wrap close(), use closesocket() on WIN32/WinSock.