RBE state storage

[knolleary]

@dceejay

One of the RBE modes is to ignore first value so this can be used for exactly that scenario

Ah yes, forgot that was there already. But that only solves one part of it. You still need to create the extra flows to store the value and reinject it at start up. Certainly less complicate with the ignore inital value option in the RBE node - and that has probably solved the problem for users up to now.

But it's a reasonable discussion - which we've flirted with a few times before - about making more wide use of node-context in the core nodes to do exactly what it was designed for.