Hierarchical stream connectors are not handled correctly

[Francesco Casella]

If a hierarchical connector contains N > 1 stream connectors, the compiler complains:

Invalid stream connector XXX: A stream connector must have exactly one flow variable, this connector has N flow variables.

This is incorrect: each individual connector has its own flow variable, and these should not be mixed up when generating the expressions for inStream() and actualStream() involving them.

In order to handle hierarchical stream connectors, one should not just flatten them out. Separate connection sets should be built for each individual stream connector in the hierarchical connector

The attached package demonstrate the problem

[Francesco Casella]

Test package