jet hypo - mostly fixing code that handles identical Conditions
Previously, identical conditions were recognised early on in the jet configuration. The approach broke down when we introduced the constraint of one Condition per node.
The new approach is to build the single-Condition node tree, then for each node, check whether the child nodes include identical nodes. If this is the case, all but one of the identical child nodes are deleted, and the multiplicity of the sole surviving child node is set appropriately.
It turns out this also brings about code simplification.
This commit also includes improvements to code testing tools.
Note - the local branch is incorrectly labelled as 22724. This should be 22727