Signed-off-by: NLi Yang <liyang.fnst@cn.fujitsu.com>

When editing guest's XML (on QEMU), it was possible to add multiple
listen elements into graphics parent element. However QEMU does not
support listening on multiple addresses. Configuration is tested for
multiple 'listen address' and if positive, an error is raised.

https://bugzilla.redhat.com/show_bug.cgi?id=1119212

There are some stateless drivers which implement subdrivers
(typically vbox and its own network and storage subdrivers). However,
as of ba5f3c7c the vbox driver lives in the daemon, not the
client library. This means, in order for vbox (or any stateless domain
driver) to use its subdrivers, it must register before the general
drivers. Later, when the virConnectOpen function goes through the
subdrivers, stateless drivers are searched first. If the connection
request is aiming at stateless driver, it will be opened. Otherwise
the generic subdriver is opened.

The other change done in this commit is moving interface module load a
bit earlier to match the ordering in case libvirt is built without
driver modules.
Reported-by: NTaowei Luo <uaedante@gmail.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Patch adding the command forgot to add the man page entry.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1130379

After this patch, we will have only one common domain driver.
So, the rewritten on domain driver is finished in this patch.

Four functions are rewrite in this patch, that is:
vboxNodeGetInfo
vboxNodeGetCellsFreeMemory
vboxNodeGetFreeMemory
vboxNodeGetFreePages
Since these functions has nothing to do with vbox,
it can be directly moved to vbox_common.c. So, I
merged these things into one patch.

The vboxDomainSnapshotCreateXML integrated the snapshot redefine
with this patch:
http://www.redhat.com/archives/libvir-list/2014-May/msg00589.html
This patch introduced vboxSnapshotRedefine in vboxUniformedAPI to
enable the features.

This patch replace all version specified APIs to the uniformed api,
then, moving the whole implementation to vbox_common.c. As there
is only API level changes, the behavior of the function doesn't
change.

Some old version's defects has brought to the new one. The already
known things are:
    *goto cleanup in a loop without releasing the pointers in the
    loop.
    *When function failed after machine unregister, no roll back
    to recovery it and the virtual machine would disappear.

Since vboxDomainAttachDeviceImple not used in vbox_tmpl.c, it has
been deleted.