tools/virsh-domain-monitor.c
   * Introduce new command : domifaddr
     Usage: domifaddr <domain> [interface] [--full] [--source lease|agent]

     Example outputs:
     virsh # domifaddr f20
     Name       MAC address          Protocol     Address
     -------------------------------------------------------------------------------
     lo         00:00:00:00:00:00    ipv4         127.0.0.1/8
     -          -                    ipv6         ::1/128
     vnet0      52:54:00:2e:45:ce    ipv4         10.1.33.188/24
     -          -                    ipv6         2001:db8:0:f101::2/64
     -          -                    ipv6         fe80::5054:ff:fe2e:45ce/64
     vnet1      52:54:00:b1:70:19    ipv4         192.168.105.201/16
     -          -                    ipv4         192.168.201.195/16
     -          -                    ipv6         fe80::5054:ff:feb1:7019/64
     vnet2      52:54:00:36:2a:e5    N/A          N/A
     vnet3      52:54:00:20:70:3d    ipv4         192.168.105.240/16
     -          -                    ipv6         fe80::5054:ff:fe20:703d/64

     virsh # domifaddr f20 eth1 --source lease
     Name       MAC address          Protocol     Address
     -------------------------------------------------------------------------------
     vnet1      52:54:00:b1:70:19    ipv4         192.168.105.201/16
     -          -                    ipv4         192.168.201.195/16
     -          -                    ipv6         fe80::5054:ff:feb1:7019/64

     virsh # domifaddr f20 eth0 --source agent --full
     Name       MAC address          Protocol     Address
     -------------------------------------------------------------------------------
     eth0       52:54:00:2e:45:ce    ipv4         10.1.33.188/24
     eth0       52:54:00:2e:45:ce    ipv6         2001:db8:0:f101::2/64
     eth0       52:54:00:2e:45:ce    ipv6         fe80::5054:ff:fe2e:45ce/64

tools/virsh.pod
   * Document new command
Signed-off-by: NNehal J Wani <nehaljw.kkd1@gmail.com>