Linty fixes

This commit fixes a number of warnings shown in compilation with MSVC.  No behavioral changes intended.  I did not fix signed/unsigned warnings.

src/widgets/NumericTextCtrl.cpp

@@ -596,6 +596,7 @@ return theArray.Get();
       (NumericConverter::Type type)
    {
       switch (type) {
+         default:
          case NumericConverter::TIME:
             return TimeConverterFormats();
          case NumericConverter::FREQUENCY: