dnsmasq: backport latest pre2.81 patches

dnsmasq: backport latest pre2.81 patches

f52bb5b fix previous commit
18eac67 Fix entries in /etc/hosts disabling static leases.
f8c77ed Fix removal of DHCP_CLIENT_MAC options from DHCPv6 relay replies.
4bf62f6 Tidy cache_blockdata_free()
9c0d445 Fix e7bfd556c079c8b5e7425aed44abc35925b24043 to actually work.
2896e24 Check for not(DS or DNSKEY) in is_outdated_cname_pointer()
a90f09d Fix crash freeing negative SRV cache entries.
5b99eae Cache SRV records.
2daca52 Fix typo in ra-param man page section.
2c59473 File logic bug in cache-marshalling code. Introduced a couple of commits back.
cc921df Remove nested struct/union in cache records and all_addr.
ab194ed Futher address union tidying.
65a01b7 Tidy address-union handling: move class into explicit argument.
bde4647 Tidy all_addr union, merge log and rcode fields.
e7bfd55 Alter DHCP address selection after DECLINE in consec-addr mode. Avoid offering the same address after a recieving a DECLINE message to stop an infinite protocol loop. This has long been done in default address allocation mode: this adds similar behaviour when allocaing addresses consecutively.

The most relevant fix for openwrt is 18eac67 (& my own local f52bb5b
which fixes a missing bracket silly) To quote the patch:

It is possible for a config entry to have one address family specified by a
dhcp-host directive and the other added from /etc/hosts. This is especially
common on OpenWrt because it uses odhcpd for DHCPv6 and IPv6 leases are
imported into dnsmasq via a hosts file.

To handle this case there need to be separate *_HOSTS flags for IPv4 and IPv6.
Otherwise when the hosts file is reloaded it will clear the CONFIG_ADDR(6) flag
which was set by the dhcp-host directive.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>