* Makefile.common (CFLAGS_COMMON): Add temporary define to work around w32api

problem.

* cygwin/winlean.h: Define constant which will be needed eventually.  Remove
hack in favor of another hack.
* cygwin/lib/crt0.h: Use "winlean.h".

winsup/cygwin/lib/crt0.h

@@ -12,7 +12,7 @@ details. */
 extern "C" {
 #endif
 
-#include <windows.h>
+#include "winlean.h"
 struct per_process;
 typedef int (*MainFunc) (int argc, char *argv[], char **env);
 int __stdcall _cygwin_crt0_common (MainFunc, struct per_process *);