item_updater: Add version dbus object.

Implementing the Version object under item_updater helps
to retain the version of the active images after the bmc
is rebooted and the image_dir no longer holds version file.

Change-Id: I55349bbc62b212b4e034239f4f6743129c8b1070
Signed-off-by: Saqib Khan <khansa@us.ibm.com>
3 files changed