scm automatic cleanups.

header fixes

slirp_dns.c: replaces scanf based resolv.conf parsing with new parser. RCPSF_IGNORE_IPV6 passed to parser, perhaps this should be changed for DNSProxy. comments added about converting loopback to alias and back, storing the list of nameservers and domain names , perhaps don't need queue and list anymore.

Introduces resolv.conf parser replacement for Slirp and Main. resolv_conf_parser.c - parser. resolv_conf_parser.h - interface to parser.