Break out more header info into separate files. Use appropriate header files

throughout.
* shared.h: Remove.
* cygwin_version.h: New file.
* delqueue.h: New file.
* environ.h: New file.
* host_dependent.h: New file.
* perprocess.h: New file.
* registry.h: New file.
* security.h: New file.

winsup/cygwin/ntea.cc

@@ -10,9 +10,10 @@ This software is a copyrighted work licensed under the terms of the
 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
 details. */
 
-#include <winsup.h>
+#include "winsup.h"
 #include <stdio.h>
 #include <stdlib.h>
+#include "security.h"
 
 /* Default to not using NTEA information */
 BOOL allow_ntea = FALSE;