Update wxWidgets to 3.1.0

From wxWidgets master 81570ae070b35c9d52de47b1f14897f3ff1a66c7.

include/wx/defs.h -- __w64 warning disable patch by comex brought forward.

include/wx/msw/window.h -- added GetContentScaleFactor() which was not implemented on Windows but is necessary for wxBitmap scaling on Mac OS X so it needs to work to avoid #ifdef-ing the code.

src/gtk/window.cpp -- Modified DoSetClientSize() to direct call wxWindowGTK::DoSetSize() instead of using public wxWindowBase::SetSize() which now prevents derived classes (like wxAuiToolbar) intercepting the call and breaking it. This matches Windows which does NOT need to call DoSetSize internally. End result is this fixes Dolphin's debug tools toolbars on Linux.

src/osx/window_osx.cpp -- Same fix as for GTK since it has the same issue.

src/msw/radiobox.cpp -- Hacked to fix display in HiDPI (was clipping off end of text).

Updated CMakeLists for Linux and Mac OS X. Small code changes to Dolphin to fix debug error boxes, deprecation warnings, and retain previous UI behavior on Windows.

Externals/wxWidgets3/include/wx/colourdata.h

@@ -26,6 +26,8 @@ public:
 
     void SetChooseFull(bool flag) { m_chooseFull = flag; }
     bool GetChooseFull() const { return m_chooseFull; }
+    void SetChooseAlpha(bool flag) { m_chooseAlpha = flag; }
+    bool GetChooseAlpha() const { return m_chooseAlpha; }
     void SetColour(const wxColour& colour) { m_dataColour = colour; }
     const wxColour& GetColour() const { return m_dataColour; }
     wxColour& GetColour() { return m_dataColour; }
@@ -45,7 +47,10 @@ public:
     wxColour        m_custColours[NUM_CUSTOM];
     bool            m_chooseFull;
 
-    DECLARE_DYNAMIC_CLASS(wxColourData)
+protected:
+    bool            m_chooseAlpha;
+
+    wxDECLARE_DYNAMIC_CLASS(wxColourData);
 };
 
 #endif // _WX_COLOURDATA_H_