Create strike-through wxGraphicsFont objects in wxOSX

Honour wxFONTFLAG_UNDERLINED in wxGraphicsFont::CreateFont() overload taking
flags.

See https://github.com/wxWidgets/wxWidgets/pull/187

docs/changes.txt

@@ -223,7 +223,7 @@ wxOSX/Cocoa:
 - Fix wxEVT_CHAR for non-BMP Unicode characters (ARATA Mizuki).
 - Add wxTE_AUTO_URL support to wxTextCtrl (Igor Korot).
 - Add support for wxEVT_COMBOBOX_{DROPDOWN, CLOSEUP} events (Igor Korot).
-- Implement strike-through support in wxFont (Igor Korot).
+- Implement strike-through support in wxFont (Igor Korot, Daniel Kulp).
 - Provide native implementation of wxStandardPaths (Tobias Taschner).
 - Add wxTE_{RIGHT,CENTER} support for multiline wxTextCtrl (Andreas Falkenhahn).
 - Don't leave wxSlider labels shown when the slider itself is hidden.

src/osx/carbon/graphics.cpp

@@ -2875,6 +2875,9 @@ wxMacCoreGraphicsRenderer::CreateFont(double sizeInPixels,
                 (flags & wxFONTFLAG_UNDERLINED) != 0,
                 facename);
 
+    if ( flags & wxFONTFLAG_STRIKETHROUGH )
+        font.MakeStrikethrough();
+
     wxGraphicsFont f;
     f.SetRefData(new wxMacCoreGraphicsFontData(this, font, col));
     return f;