Introduce a new API to get libvirt version. It is worth noting, that
libvirt-admin and libvirt share the same version number. Unfortunately,
our existing API isn't generic enough to be used with virAdmConnectPtr
as well. Also this patch wires up this API to the virt-admin client
as a generic cmdVersion command.
As we need a client disconnect handler, we also need a mechanism to register
such handlers for a client. This patch introduced both the close callbacks and
also the client vshAdmCatchDisconnect handler to be registered with it. By
registering the handler we still need to make sure the client can react to
daemon's events like disconnect or keepalive, so asynchronous I/O event polling
is necessary to be enabled too.
Since most of our APIs rely on an acive functional connection to a daemon and
we have such a mechanism in libvirt already, there's need to have such a way in
libvirt-admin as well. By introducing a new public API, this patch provides
support to check for an active connection.
This patch introduces virt-admin client which is based on virsh client,
but had to reimplement several methods to meet virt-admin specific needs
or remove unnecessary virsh specific logic.
