domifaddr: Implement the remote protocol

domifaddr: Implement the remote protocol

daemon/remote.c
   * Define remoteSerializeDomainInterface, remoteDispatchDomainInterfaceAddresses

src/remote/remote_driver.c
   * Define remoteDomainInterfaceAddresses

src/remote/remote_protocol.x
   * New RPC procedure: REMOTE_PROC_DOMAIN_INTERFACE_ADDRESSES
   * Define structs remote_domain_ip_addr, remote_domain_interface,
     remote_domain_interfaces_addresse_args, remote_domain_interface_addresses_ret
   * Introduce upper bounds (to handle DoS attacks):
     REMOTE_DOMAIN_INTERFACE_MAX = 2048
     REMOTE_DOMAIN_IP_ADDR_MAX = 2048
     Restrictions on the maximum number of aliases per interface were
     removed after kernel v2.0, and theoretically, at present, there
     are no upper limits on number of interfaces per virtual machine
     and on the number of IP addresses per interface.

src/remote_protocol-structs
   * New structs added

Signed-off-by: Nehal J Wani <nehaljw.kkd1@gmail.com>