There are lots of macro declarations in vbox_common.c,
vbox_network.c, and the coming vbox_storage.c which simply the API
calling. Since they are totally the same. We shouldn't keep three
copies of that, so they are moved to vbox_common.h.
Note: The macros are quite different from those in vbox_tmpl.c,
because they are using different API.
This patch seperate the domain driver and the network driver.
libvirt_driver_vbox_impl.la has been linked in the network driver.
So that the version specified codes in vbox_V*.c would only be
compiled once.
The vboxGetNetworkDriver provides a simple interface to get vbox
network driver.
This patch rewrites two public APIs. They are vboxNetworkUndefine
and vboxNetworkDestroy. They use the same core function
vboxNetworkUndefineDestroy. I merged it in one patch.
This patch actually contains two public API, virNetworkDefineXML
and virNetworkCreateXML. They use the same core function
vboxNetworkDefineCreateXML. So I merged it together.
