Remove obsolete wxCHECK_W32API_VERSION() checks

The latest of those checks tested for w32 API 3.3, which is older than
MinGW 3.4 released which is more than 13 years old, so we can safely
drop them (let alone checks for prehistoric 0.5 w32 API).

This incidentally fixes compilation errors due to the use of
wxCHECK_W32API_VERSION() in wx/msw/winundef.h which was now (since
the changes of 8c572c0a77) included before
this macro was defined.

include/wx/msw/gccpriv.h

@@ -100,46 +100,6 @@
     #define __CYGWIN10__
 #endif
 
-/* Mingw runtime 1.0-20010604 has some missing _tXXXX functions,
-   so let's define them ourselves: */
-#if defined(__GNUWIN32__) && wxCHECK_W32API_VERSION( 1, 0 ) \
-    && !wxCHECK_W32API_VERSION( 1, 1 )
-    #ifndef _tsetlocale
-      #if wxUSE_UNICODE
-      #define _tsetlocale _wsetlocale
-      #else
-      #define _tsetlocale setlocale
-      #endif
-    #endif
-    #ifndef _tgetenv
-      #if wxUSE_UNICODE
-      #define _tgetenv _wgetenv
-      #else
-      #define _tgetenv getenv
-      #endif
-    #endif
-    #ifndef _tfopen
-      #if wxUSE_UNICODE
-      #define _tfopen _wfopen
-      #else
-      #define _tfopen fopen
-      #endif
-    #endif
-#endif
-
-/* current (= before mingw-runtime 3.3) mingw32 headers forget to
-   define _puttchar, this will probably be fixed in the next versions but
-   for now do it ourselves
- */
-#if defined( __MINGW32__ ) && \
-        !wxCHECK_MINGW32_VERSION(3,3) && !defined( _puttchar )
-    #ifdef wxUSE_UNICODE
-        #define  _puttchar   putwchar
-    #else
-        #define  _puttchar   puttchar
-    #endif
-#endif
-
 /*
     Traditional MinGW (but not MinGW-w64 nor TDM-GCC) omits many POSIX
     functions from their headers when compiled with __STRICT_ANSI__ defined.