miscellaneous bugfixes and indentation fixes

miscellaneous bugfixes and indentation fixes

* srvx.conf.example: Clarify comment about "default_hostmask" setting.

* patches/sethost13.diff: Forward port of sethost patch, from Reed Loden.

* src/opserv.c (cmd_kickbanall): Free mod_chanmode_change after use.

* src/proto-p10.c (cmd_whois): Fix indentation and show real server to opers.

* src/tools.c (string_buffer_append_vprintf): Avoid a possible buffer overrun.
git-archimport-id: srvx@srvx.net--2004-srvx/srvx--devo--1.3--patch-70