Purged dependence on ssh_connection from channel.c. Updated all users.

Rev: src/channel.c:1.125.2.1
Rev: src/channel.h:1.77.2.1
Rev: src/channel_commands.c:1.30.2.1
Rev: src/channel_commands.h:1.21.2.1
Rev: src/client.c:1.166.2.1
Rev: src/client_pty.c:1.27.2.1
Rev: src/client_x11.c:1.26.2.1
Rev: src/gateway_channel.c:1.18.2.1
Rev: src/gateway_commands.c:1.24.2.1
Rev: src/lshd-userauth.c:1.1.2.5
Rev: src/read_data.c:1.37.2.1
Rev: src/server_session.c:1.103.2.1
Rev: src/server_x11.c:1.21.2.1
Rev: src/tcpforward.c:1.69.2.1
Rev: src/tcpforward_commands.c:1.47.2.1