Add settings application

Implement settings d-bus interfaces.

Define a settings policy file (this commit checks in an example YAML
based policy), based on which code for a settings manager will be
generated via a python script.
This settings manager composes and places desired settings objects on
the bus.

The policy file can be supplied by a system specific bitbake recipe.

Resolves openbmc/openbmc#1487.

Change-Id: Ice0d3b319d9466824cef323a6915eb20ca5cae5c
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
7 files changed