Introduce a number of new APIs to expose some boolean properties
of objects, which cannot otherwise reliably determined, nor are
aspects of the XML configuration.
* virDomainIsActive: Checking virDomainGetID is not reliable
since it is not possible to distinguish between error condition
and inactive domain for ID of -1.
* virDomainIsPersistent: Check whether a persistent config exists
for the domain
* virNetworkIsActive: Check whether the network is active
* virNetworkIsPersistent: Check whether a persistent config exists
for the network
* virStoragePoolIsActive: Check whether the storage pool is active
* virStoragePoolIsPersistent: Check whether a persistent config exists
for the storage pool
* virInterfaceIsActive: Check whether the host interface is active
* virConnectIsSecure: whether the communication channel to the
hypervisor is secure
* virConnectIsEncrypted: whether any network based commnunication
channels are encrypted
NB, a channel can be secure, even if not encrypted, eg if it does
not involve the network, like a UNIX socket, or pipe.
* include/libvirt/libvirt.h.in: Define public API
* src/driver.h: Define internal driver API
* src/libvirt.c: Implement public API entry point
* src/libvirt_public.syms: Export API symbols
* src/esx/esx_driver.c, src/lxc/lxc_driver.c,
src/interface/netcf_driver.c, src/network/bridge_driver.c,
src/opennebula/one_driver.c, src/openvz/openvz_driver.c,
src/phyp/phyp_driver.c, src/qemu/qemu_driver.c,
src/remote/remote_driver.c, src/test/test_driver.c,
src/uml/uml_driver.c, src/vbox/vbox_tmpl.c,
src/xen/xen_driver.c: Stub out driver tables