Add system_state dbus property

Add system_state property to keep track of the system
state across reboots.
Include the generated settings_file.py since some build
machines cannot have the yaml python module installed. This
file will be removed once the code is ported to C in the next rework.
Add the path where the settings will be stored in bmc:
/var/lib/obmc/
Address review comments from the initial commit.
3 files changed