message: Use wxIcon for list control's icons
  Change m_colIcon bitmap renderer to use wxIcon instead of wxBitmap.
  On Windows, drawing icons is much more efficient than wxBitmap with
  alpha channel, while being pretty much the same thing on other
  platforms.
  See
diff: @@ -296,11 +296,11 @@ class PoeditListCtrl : public wxDataViewCtrl
  wxColour m_clrID, m_clrInvalid, m_clrFuzzy;
  wxString m_clrContextFg, m_clrContextBg;
  - wxBitmap m_iconComment, m_iconBookmark, m_iconError, m_iconWarning;
  + wxIcon m_iconComment, m_iconBookmark, m_iconError, m_iconWarning;
  #if defined(__WXGTK__) && !wxCHECK_VERSION(3,0,3)
  #define HAS_BROKEN_NULL_BITMAPS
  - wxBitmap m_nullBitmap;
  + wxIcon m_nullBitmap;
  #endif
  };
  