nwrap: Use nwrap vectors as memory backend for getaddrinfo() and gethostbyname()

nwrap: Use nwrap vectors as memory backend for getaddrinfo() and gethostbyname()

Previous patches introduced nwrap vectors and hash functions.
This patch will join all together.

Main purpose of this patch is:
	- support more records per hostname.
	  For example: hostname now can have associated IPv4 and IPv6 address.
	- better handling of big number of hostname records

Signed-off-by: Robin Hack <hack.robin@gmail.com>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Michael Adam <obnox@samba.org>