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.

include/wx/propgrid/propgrid.h

@@ -593,7 +593,7 @@ enum wxPG_INTERNAL_FLAGS
 // used to do the very same thing, but it hasn't been updated for a while
 // and it is currently deprecated.
 // Please note that most member functions are inherited and as such not
-// documented heree. This means you will probably also want to read
+// documented here. This means you will probably also want to read
 // wxPropertyGridInterface class reference.
 // To process input from a propertygrid control, use these event handler
 // macros to direct input to member functions that take a wxPropertyGridEvent

include/wx/propgrid/propgridiface.h

@@ -540,7 +540,7 @@ public:
 
     // Hides or reveals a property.
     // hide - If true, hides property, otherwise reveals it.
-    // flags - By default changes are applied recursively. Set this paramter
+    // flags - By default changes are applied recursively. Set this parameter
     //   wxPG_DONT_RECURSE to prevent this.
     bool HideProperty( wxPGPropArg id,
                        bool hide = true,