add the wxFont(const wxSize& pixelSize, ...) ctor to all ports; add some wxCHECK_MSGs to ensure that the wxSize objects contains non-negative arguments; document that passing zero for the width parameter is allowed; other minor doc fixes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59564 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/os2/font.h

@@ -50,7 +50,19 @@ public:
     {
         Create(size, family, style, weight, underlined, face, encoding);
     }
-
+    
+    wxFont(const wxSize& pixelSize,
+           wxFontFamily family,
+           wxFontStyle style,
+           wxFontWeight weight,
+           bool underlined = false,
+           const wxString& face = wxEmptyString,
+           wxFontEncoding encoding = wxFONTENCODING_DEFAULT)
+    {
+        Create(10, family, style, weight, underlined, face, encoding);
+        SetPixelSize(pixelSize);
+    }
+    
     bool Create(int size,
                 wxFontFamily family,
                 wxFontStyle style,