Step 6.1: Separate MockExpectedCall interface
Step 6.2: Rename MockExpectedFunctionCall.h MockExpectedCall.h
Step 6.2: Rename MockExpectedFunctionCall.cpp to MockExpectedCall.cpp
Step 6.3: Separate MockActualCall interface
Step 6.4: Rename MockActualFunctionCall.h to MockActualCall.h
Step 6.4: Rename MockActualFunctionCall.cpp to MockActualCall.cpp