Merge branch 'franred/drop-rebase' of roadtrain.codethink.co.uk:genivi/boot-manager

Merge into one process, change D-Bus interfaces and write LUC to file

The following changes were made:
- Restructure the D-Bus interfaces:
--  The old boot manager interface is removed, we are no longer
    interested in being a remote controller of systemd.
--  The LUC Handler has been rewritten and renamed to
    org.genivi.BootManager1.BootManager. It has the following
    methods:
---   BeginLUCRegistration() initializes the LUC registration
      sequence at shutdown.
---   RegisterWithLUC(a{ias}) registers one or more apps with
      different LUC types.
---   FinishLUCRegistration() finishes the LUC registration
      sequence and atomically replaces the previous LUC.
--  The legacy application handler has been renamed to
    org.genivi.BootManager1.LegacyAppHandler. This interface
    is not for external use. It is meant only for the command-
    line interface to communicate with the boot manager.
--  The LastUserContext property has been removed.
- The last user context is now stored in a file rather than with
  GSettings. This was requested after the Gothenburg F2F, but is
  included because it is easier to make the change now than modify
  GSettings only to remove it later.
- All services run as part of the same process (i.e. boot-manager).
- All services run on the system bus. Because of this, the boot
  manager's command-line interface is handled differently, as the
  previous implementation, using GApplication, does not work on the
  system bus. The command-line interface now works by making a D-Bus
  call to the boot manager service, instead of using GApplication's
  remote command-line functionality.
- The LUC Handler tests have been renamed to the boot manager
  tests, and are changed in line with the new interface methods.