Server: Restart on Reboot if it was running

[John-Holt-Tessella]

As a scientist if my server reboots I want IBEX to restart itself but only if it was running before the reboot. This is so rebooting a server doesn't start IBEX on a server where SECI was running on its own.

It should achieve this by writing a file on start to var settings which indicates that IBEX has started and removing it on stop.
On start full (not mini) it should also remove the SECI running file if it exists. @mattclarke will let you know where this is stored.

[John-Holt-Tessella]

Edit https://github.com/ISISComputingGroup/ibex_developers_manual/wiki/Startup-and-Shutdown to put full behaviour in.