Added support for network interface model setting

tests/xmconfigdata/test-paravirt-net-e1000.cfg

@@ -0,0 +1,12 @@
+name = "XenGuest1"
+uuid = "c7a5fdb0-cdaf-9455-926a-d65c16db1809"
+maxmem = 579
+memory = 394
+vcpus = 1
+bootloader = "/usr/bin/pygrub"
+on_poweroff = "destroy"
+on_reboot = "restart"
+on_crash = "restart"
+vfb = [ "type=vnc,vncunused=1,vnclisten=127.0.0.1,vncpasswd=123poi" ]
+disk = [ "phy:/dev/HostVG/XenGuest1,xvda,w" ]
+vif = [ "mac=00:16:3E:66:94:9C,model=e1000,ip=192.168.0.9" ]

tests/xmconfigdata/test-paravirt-net-e1000.xml

@@ -0,0 +1,28 @@
+<domain type='xen'>
+  <name>XenGuest1</name>
+  <uuid>c7a5fdb0-cdaf-9455-926a-d65c16db1809</uuid>
+  <bootloader>/usr/bin/pygrub</bootloader>
+  <currentMemory>403456</currentMemory>
+  <memory>592896</memory>
+  <vcpu>1</vcpu>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>restart</on_crash>
+  <devices>
+    <disk type='block' device='disk'>
+      <driver name='phy'/>
+      <source dev='/dev/HostVG/XenGuest1'/>
+      <target dev='xvda'/>
+    </disk>
+    <interface type='bridge'>
+      <mac address='00:16:3E:66:94:9C'/>
+      <ip address='192.168.0.9'/>
+      <model type='e1000'/>
+    </interface>
+    <input type='mouse' bus='xen'/>
+    <graphics type='vnc' port='-1' listen='127.0.0.1' passwd='123poi'/>
+    <console type='pty'>
+      <target port='0'/>
+    </console>
+  </devices>
+</domain>