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

include/wx/msw/winundef.h

@@ -365,13 +365,9 @@
 
 #ifdef IsMaximized
     #undef IsMaximized
-    inline BOOL IsMaximized(HWND WXUNUSED_IN_WINCE(hwnd))
+    inline BOOL IsMaximized(HWND hwnd)
     {
-#ifdef __WXWINCE__
-        return FALSE;
-#else
         return IsZoomed(hwnd);
-#endif
     }
 #endif
 
@@ -379,13 +375,9 @@
 
 #ifdef GetFirstChild
     #undef GetFirstChild
-    inline HWND GetFirstChild(HWND WXUNUSED_IN_WINCE(hwnd))
+    inline HWND GetFirstChild(HWND hwnd)
     {
-#ifdef __WXWINCE__
-        return 0;
-#else
         return GetTopWindow(hwnd);
-#endif
     }
 #endif
 
@@ -462,15 +454,6 @@
 #endif
 
 
-#if defined(__WXWINCE__) && defined(DrawIcon) //#ifdef DrawIcon
-    #undef DrawIcon
-    inline BOOL DrawIcon(HDC hdc, int x, int y, HICON hicon)
-    {
-        return DrawIconEx(hdc,x,y,hicon,0,0,0,NULL, DI_NORMAL) ;
-    }
-#endif
-
-
 // GetWindowProc
 //ifdef GetWindowProc
 //   #undef GetWindowProc