[$] Kexec handover and the live update orchestrator

Rebooting a computer ordinarily brings an abrupt end to any state built up
by the old system; the new kernel starts from scratch. There are, however,
people who would like to be able to reboot their systems without
disrupting the workloads running therein. Various developers are currently
partway through the project of adding this capability, in the form of
'kexec handover' and the 'live update orchestrator', to the kernel.