package/dnsmasq: allow /etc/config/dhcp to specify --address arguments

Add a config list to the 'config dnsmasq' section to specify fixed DNS
addresses.

For example:

  config dnsmasq:
	[snip]
	list address '/example.com/192.168.0.1'

will result in the argument '-A /example.com/192.168.0.1' to the dnsmasq
options. This configures dnsmasq to return the specified IP for any
queries to '*.example.com' names.

Useful for overriding lookups to a range of DNS names.

[jow: "append args" -> "xappend", "-A" -> "--address"]

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

SVN-Revision: 32624