src/debug.c, src/disconnect.c, src/proxy.c,
src/proxy_x11forward.c, src/server.c, src/server_keyexchange.c,
src/server_userauth.c: Packet handlers should no longer free
packets.

Rev: src/client.c:1.112
Rev: src/client_keyexchange.c:1.58
Rev: src/client_userauth.c:1.47
Rev: src/debug.c:1.35
Rev: src/disconnect.c:1.21
Rev: src/proxy.c:1.11
Rev: src/proxy_x11forward.c:1.5
Rev: src/server.c:1.66
Rev: src/server_keyexchange.c:1.48
Rev: src/server_userauth.c:1.32