Fix spelling in comments and documentation using codespell

Apply the utility from https://github.com/codespell-project/codespell/
to fix spelling issues in the headers under both include and interface
directories and add a file with a couple of exceptions.

The exact command line used was:

    $ codespell -w -I misc/scripts/codespell.ignore -i 3 in*

include/wx/propgrid/property.h

@@ -1037,7 +1037,7 @@ public:
                                 wxPGValidationInfo& validationInfo ) const;
 
     // Converts text into wxVariant value appropriate for this property.
-    // Prameters:
+    // Parameters:
     // variant - On function entry this is the old value (should not be
     //   wxNullVariant in normal cases). Translated value must be assigned
     //   back to it.