[package] dnsmasq: introduce "add_local_hostname" and "add_local_domain" options

[package] dnsmasq: introduce "add_local_hostname" and "add_local_domain" options
 - add_local_domain defaults to 1 and controls whether the local domain is written as search directive to the local resolv.conf
 - add_local_hostname defaults to 1 and controls whether A and PTR records are created automatically for the local hostname
These change supersedes http://patchwork.openwrt.org/patch/2207/ and http://patchwork.openwrt.org/patch/2208/

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@32570 3c298f89-4303-0410-b956-a3cf2f4a3e73