Cache variables scope

Under Flow Engine context, all cache variables (both external and internal) defined for the flow instance, go out of scope when the flow instance completes execution. It does not affect the cache variables of the other instance.

Under non-flow engine context, for example, running a map under Command Server, using flow library functions in the map rules, all cache variables defined with the mapping functions go out of scope when the top map finishes execution. All cache variables defined are visible with top and RUN maps of the map. Each map instance execution gets its own set of cache variables and no two map instances share the same set of the variables.