ipv4: new default to send gratuitous arp

Consider new suse ifcfg variable default SEND_GRATUITOUS_ARP=auto
for arp-notify, enabling to send gratuitous arp by default, when
duplicate IPv4 check is enabled via arp-verify/CHECK_DUPLICATE_IP
and the check were successful (bnc#879911,fate#314399).
arp: no verify/notify if not applicable for device
ifconfig: fix for an unitialized error return code
dbus: do not close shared connections (bnc#880124)
compat: apply DHCLIENT_ROUTE_PRIORITY (bnc#879842)
dhcp4: set a protocol dhcp hint to all routes
addrconf: added a lease priority function
routes: added equal destination/gateway utilities
server: do not apply duplicate routes (bnc#879842)
Merge pull request #262 from mtomaschewski/auto-garp
Merge pull request #263 from mtomaschewski/bnc880124
Merge pull request #266 from mtomaschewski/route-dups

do not apply duplicate routes (bnc#879842)
version 0.5.27
ifdown: disable unused function
fsm: Introduce ni_fsm_state_t type
server: Discover initial client-state and persistent

Do no discover initial values from the client.
fsm: Update client-info only on final state
fsm: Schedule device-ready state for physical devices
fsm: Resolve devices hierarchy before marking
fsm: Clean client-info origin and UUID on ifdown