Remove "wants_reads" field from struct io_fd.

Remove "wants_reads" field from struct io_fd.

Everybody wants read information, so give it to them!

src/ioset-epoll.c (ioset_epoll_events): Make EPOLLIN unconditional.

src/ioset-impl.h (fd_wants_reads): Delete.

src/ioset-select.c (ioset_select_loop): Unconditionally set read bit for fd.

src/ioset.c (ioset_add): Add fd to engine after marking it non-blocking.
  (ioset_buffered_reads): Remove check for fd->wants_reads.

src/ioset.h (struct io_fd): Delete "wants_reads" field.

src/mod-qserver.c (qserver_readable): Add missing newline.
  (qserver_accept): Delete assignment to fd->wants_reads.

src/mod-sockcheck.c (sockcheck_connected): Delete assignment to
    fd->wants_reads.

src/proto-common.c (create_socket_client): Delete assignment to
    fd->wants_reads.
git-archimport-id: srvx@srvx.net--2006/srvx--devo--1.3--patch-56