In preparation for making a private object, create accessor API's for
consumer storage functions to use:

    virStoragePoolObjGetDef
    virStoragePoolObjSetDef
    virStoragePoolObjGetNewDef
    virStoragePoolObjDefUseNewDef
    virStoragePoolObjGetConfigFile
    virStoragePoolObjSetConfigFile
    virStoragePoolObjGetAutostartLink
    virStoragePoolObjIsActive
    virStoragePoolObjSetActive
    virStoragePoolObjIsAutostart
    virStoragePoolObjSetAutostart
    virStoragePoolObjGetAsyncjobs
    virStoragePoolObjIncrAsyncjobs
    virStoragePoolObjDecrAsyncjobs
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>