Persist changes to settings

Persist changes made to settings, if any, such that those changes can be
restored upon a reboot.

Use Cereal for serialization of the settings' properties. Since the
settings code is generated based on a system specific settings policy,
generate the serialization code as well such that only relevant settings
are serialized.

Resolves openbmc/openbmc#1764.

Change-Id: Id8bd84a9455cf4348b22f255d038b050d004eb7c
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
4 files changed