Add watch on D-Bus object paths

Clients specify the object paths to watch in the config yaml.

Example yaml file and parser changes are pushed in separate
patch

Callbacks are invoked based on the watch type created i.e
interfaceadded/interfaceremoved

Change-Id: Icb7b9bf4c072f8b8df33747c813a1f07b61de637
Signed-off-by: Marri Devender Rao <devenrao@in.ibm.com>
5 files changed