Display VG export status with an LVM2 PVs busy status (#160787)

Also update to use LVM terminology, such that a Physical Volume is
referred to as a member of a Volume Group.  Status of an LVM2 PV is now
displayed using one of the following messages:
    Not active (Not a member of any volume group)
    VGNAME not active
    VGNAME not active and exported
    VGNAME active

Bug #160787 - lvm support