correcting the ComboHypo dictionary including BLS exceptions

This changes correct the CompoHypoPool dictionary to include algorithms with names that are different from what is expected from the general rule that sees the CH name inherited from the step name. This is to include correctly the BLS ComboHypos that break this rule. There is no change of behaviour, but added a WARNING as log.info when this happens.

Added also some note for future developments, and made harmless changes to avoid duplicated call of collectHypoDecisionObjects.

tagging @tamartin