Remove all trailing spaces

No real changes, just clean up sources by removing trailing spaces from
all the non-generated files.

This should hopefully avoid future commits mixing significant changes
with insignificant whitespace ones.

interface/wx/html/webkit.h

@@ -35,7 +35,7 @@ public:
                     const wxSize& size = wxDefaultSize, long style = 0,
                     const wxValidator& validator = wxDefaultValidator,
                  const wxString& name = wxWebKitCtrlNameStr);
-    
+
     bool Create(wxWindow *parent,
                 wxWindowID winid,
                 const wxString& strURL,