Ignore comparisons defined for some dialogue functions

The comparisons are ignored for the functions NotCell, NotClass, NotFaction, NotRace and NotId, as in vanilla. For consistency, they are also ignored for the function NotLocal.

The value return by the place-holder implementation of MWWorld::Class::hasDetected() is changed from false to true, because almost all NPCs now return a greeting forcing to close the dialogue window otherwise. This was not the case before because all NPCs were considered having a NoLore variable, thus some responses were not available.