Fix some warnings

The warning reg. enum compare shows up when using QtCreator on Windows, but is also seen on Transifex, ie. when using Linux. Not sure about Mac.
The warning about unused-but-set-Parameter shows up when using QtCreator on Windows, but not on Transifex, ie. when using Linux. Not sure about Mac.
Both fixes should not have any ill effect on any platform, but are a bit of a brute force. Any idea for a better approach?

The "Note: No relevant classes found. No output generated." during build show up when using QtCreator on Windows, but not on Transifex, ie. when using Linux. Not sure about Mac.
I found no good way to use it on Windows only, but this may not be needed.

None of these issues is a real serious one, but the less clutter in the warnings during build, the more likely real issues are seen and dealt with.