handle boolean/enum wildcards correctly

[mvollebregt]

A boolean can only take two values. If a boolean is used as a wildcard, it cannot be matched reliably. If three booleans are used as wildcards, two of the three wildcards have the same value and are effectively the same wildcard. The same problem holds for enums.

Possible solution: rerun the matching process multiple times, with different values for the wildcards, to check if a wildcard is really matched, or just by incidence.