More allocation debugging support.

More allocation debugging support.

src/alloc-srvx.c (srvx_realloc): Reorganize.
(verify): New function.

src/common.h (verify): Define and/or declare suitably.

src/dict-splay.c (dict_splay): Verify node at each iteration.
(dict_insert, dict_remove2, dict_find, dict_delete,
dict_sanity_check): Verify entire dict.
(dict_sanity_check_node): Verify node as valid allocation.

src/hash.c (DelChannel): Verify channel before deletion.
(GetUserMode): Verify channel, user, and each modeNode.

src/mod-sockcheck.c (sockcheck_free_client): Verify client.
(sockcheck_timeout_client, sockcheck_advance, sockcheck_readable,
sockcheck_connected, sockcheck_begin_test): Likewise.
(sockcheck_queue_address): Verify cached sockcheck entries.

src/proto-p10.c (DelUser): Verify user before deletion.
git-archimport-id: srvx@srvx.net--2005-srvx/srvx--devo--1.3--patch-7