A problematic network

[Francisco Javier Díez]

This network gives an error when switching to inference and when expanding an equivalent decision tree; after saving it in ProbModelXML format, it cannot be read again. Given that these three processes are independent, I guess that the problem lies in the Elvira parser, but I am not sure.

[Iñigo Bermejo]

Fixed super-value node parsing for Elvira networks. Also added support for "unit" reserved word. Simplified IDE4-decide-test.elv as it contains the "range" reserved word, unsupported for the time being