Litron: doesn't reconnect after interlocks are tripped and reset

[Tom-Willemsen]

HIFI laser is "interlocked" by cutting network to litron PC which is in the laser cabin.

When this interlock gets tripped and then reset, the litron IOC doesn't reconnect until the IOC is restarted.

As users will sometimes go into the laser cabin to put in a manual shutter for e.g. sample changes, it's inconvenient to have to remember to manually restart the litron IOC.

Should be easy enough to test reconnection logic against an emulator (FA has one in progress already) to make sure it remakes connection & resends any appropriate initialization strings.