is a pointer to a pointer to itself, which may be changed. They no
longer return themselves (or a replacement).

Rev: src/abstract_io.h:1.5
Rev: src/blocking_write.c:1.3
Rev: src/blocking_write.h:1.3
Rev: src/client.c:1.5
Rev: src/client.h:1.4
Rev: src/debug.c:1.6
Rev: src/debug.h:1.5
Rev: src/encrypt.c:1.6
Rev: src/io.c:1.6
Rev: src/lshd.c:1.2
Rev: src/packet_dispatch.c:1.4
Rev: src/pad.c:1.6
Rev: src/read_line.c:1.3
Rev: src/read_line.h:1.4
Rev: src/read_packet.c:1.3
Rev: src/unpad.c:1.5
Rev: src/void.c:1.6
Rev: src/write_buffer.c:1.4
Rev: src/write_buffer.h:1.4
Rev: src/zlib.c:1.5