Including a soname with a public shared library is a good practice and
is required by the policy of many distributions such as Debian. The
major version of the soname distinguishes incompatible versions of the
shared library.
They can be close()d explicitly with close-file-descriptor, and
will close() on gc, but only explicitly closing the last port on
them will close the fileno. Notably needed for network sockets
where we open separate input and output ports on the same socket.
