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/html/winpars.h

@@ -249,7 +249,7 @@ private:
 
 //-----------------------------------------------------------------------------
 // wxHtmlWinTagHandler
-//                  This is basicly wxHtmlTagHandler except
+//                  This is basically wxHtmlTagHandler except
 //                  it is extended with protected member m_Parser pointing to
 //                  the wxHtmlWinParser object
 //-----------------------------------------------------------------------------