Instead of storing the IP address string in virNetwork related
structs, store the parsed virSocketAddr. This will make it
easier to add IPv6 support in the future, by letting driver
code directly check what address family is present
* src/conf/network_conf.c, src/conf/network_conf.h,
src/network/bridge_driver.c: Convert to use virSocketAddr
in virNetwork, instead of char *.
* src/util/bridge.c, src/util/bridge.h,
src/util/dnsmasq.c, src/util/dnsmasq.h,
src/util/iptables.c, src/util/iptables.h: Convert to
take a virSocketAddr instead of char * for any IP
address parameters
* src/util/network.h: Add macros to determine if an address
is set, and what address family is set.
It implements an idea to save dhcp hosts' macaddr vs. ipaddr mappings to
static file and make dnsmasq loading it with "--dhcp-hostsfile" option,
originally suggested by Dan, and can address the problem that too
many "--dhcp-host" args hitting ARG_MAX limit
* src/util/dnsmasq.h src/util/dnsmasq.c: adds the 2 new files
