Inconsistent DLL linkage-warnings

[klanderfri]

When compiling one get four error messages, one for each method in the DLL, considering inconsistent DLL linkage:

• cardreaderlibrary.cpp(7): warning C4273: 'CRLibrary::CompareCardNames': inconsistent dll linkage
• cardreaderlibrary.cpp(12): warning C4273: 'CRLibrary::ReadCardTitles': inconsistent dll linkage
• cardreaderlibrary.cpp(19): warning C4273: 'CRLibrary::GetMaxCardAmount': inconsistent dll linkage
• cardreaderlibrary.cpp(24): warning C4273: 'CRLibrary::GetResultExample': inconsistent dll linkage

• Find out what causes these warnings.
• Fix the problem causing the warnings.