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/private.h

@@ -67,12 +67,6 @@ WXDLLIMPEXP_BASE void wxSetInstance(HINSTANCE hInst);
 // define things missing from some compilers' headers
 // ---------------------------------------------------------------------------
 
-#if defined(__WXWINCE__)
-#ifndef ZeroMemory
-    inline void ZeroMemory(void *buf, size_t len) { memset(buf, 0, len); }
-#endif
-#endif // old mingw32
-
 // this defines a CASTWNDPROC macro which casts a pointer to the type of a
 // window proc
 #if defined(STRICT) || defined(__GNUC__)
@@ -146,10 +140,7 @@ extern LONG APIENTRY
 // Vc++, bcc, dmc, ow, mingw akk have _get_osfhandle() and Cygwin has
 // get_osfhandle. Others are currently unknown, e.g. Salford, Intel, Visual
 // Age.
-#if defined(__WXWINCE__)
-    #define wxGetOSFHandle(fd) ((HANDLE)fd)
-    #define wxOpenOSFHandle(h, flags) ((int)wxPtrToUInt(h))
-#elif defined(__CYGWIN__)
+#if defined(__CYGWIN__)
     #define wxGetOSFHandle(fd) ((HANDLE)get_osfhandle(fd))
 #elif defined(__VISUALC__) \
    || defined(__BORLANDC__) \
@@ -642,12 +633,6 @@ private:
 };
 
 // set the given map mode for the life time of this object
-//
-// NB: SetMapMode() is not supported by CE so we also define a helper macro
-//     to avoid using it there
-#ifdef __WXWINCE__
-    #define wxCHANGE_HDC_MAP_MODE(hdc, mm)
-#else // !__WXWINCE__
     class HDCMapModeChanger
     {
     public:
@@ -676,7 +661,6 @@ private:
 
     #define wxCHANGE_HDC_MAP_MODE(hdc, mm) \
         HDCMapModeChanger wxMAKE_UNIQUE_NAME(wxHDCMapModeChanger)(hdc, mm)
-#endif // __WXWINCE__/!__WXWINCE__
 
 // smart pointer using GlobalAlloc/GlobalFree()
 class GlobalPtr