Remove Windows CE support

Windows CE doesn't seem to be supported by Microsoft any longer. Last CE
release was in early 2013 and the PocketPC and Smartphone targets supported by
wxWidgets are long gone.

The build files where already removed in an earlier cleanup this commit
removes all files, every #ifdef and all documentation regarding the Windows CE
support.

Closes https://github.com/wxWidgets/wxWidgets/pull/81

src/msw/utilsgui.cpp

@@ -254,16 +254,7 @@ void PixelToHIMETRIC(LONG *x, LONG *y)
 
 void wxDrawLine(HDC hdc, int x1, int y1, int x2, int y2)
 {
-#ifdef __WXWINCE__
-    POINT points[2];
-    points[0].x = x1;
-    points[0].y = y1;
-    points[1].x = x2;
-    points[1].y = y2;
-    Polyline(hdc, points, 2);
-#else
     MoveToEx(hdc, x1, y1, NULL); LineTo((HDC) hdc, x2, y2);
-#endif
 }