ditch omapi_ipv6; the one place that needed it can call isc_net_probeipv6 directly.
ditch omapi_ipv6; the one place that needed it can call isc_net_probeipv6
directly.

note whether memory context is internal to the library so it can be
destroyed by omapi_lib_destroy.

destroy the handle table.

set destroyed pointers to null.

require omapi_lib_init only be called once (without omapi_lib_destroy).

each/bind9-collab,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,each/bind9-collab,each/bind9-collab,pecharmin/bind9,each/bind9-collab