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

demos/bombs/bombs.cpp

@@ -24,9 +24,7 @@
 
 #include <stdlib.h>
 
-#ifndef __WXWINCE__
-#   include <time.h>
-#endif
+#include <time.h>
 
 #ifndef wxHAS_IMAGES_IN_RESOURCES
 #   include "bombs.xpm"
@@ -34,18 +32,10 @@
 
 wxIMPLEMENT_APP(BombsApp);
 
-#ifdef __WXWINCE__
-    STDAPI_(__int64) CeGetRandomSeed();
-#endif
-
 // Called to initialize the program
 bool BombsApp::OnInit()
 {
-#ifdef __WXWINCE__
-    srand((unsigned) CeGetRandomSeed());
-#else
     srand((unsigned) time(NULL));
-#endif
 
     m_frame = new BombsFrame(&m_game);