[$] Kexec handover and the live update orchestrator

Rebooting a computer ordinarily brings an abrupt end to any state built upby the old system; the new kernel starts from scratch. There are, however,people who would like to be able to reboot their systems withoutdisrupting the workloads running therein. Various developers are currentlypartway through the project of adding this capability, in the form of"kexec handover" and the "live update orchestrator", to the kernel.