Refactors the clientmgmt package to implement the plugin versioning changes
needed for BIA v1 and overall package refactoring to support plugin versions
in different packages. This should be all that's needed to move on to
v2 for BackupItemAction. The remaining plugin types still need similar
refactoring to what's being done here for BIA before attempting a
v2 implementation.
Signed-off-by: Scott Seago <sseago@redhat.com>
