DJGPP adjustments

* Configure: Replaced -DTERMIO by -DTERMIOS in CFLAGS.

* crypto/bio/bss_dgram.c [WATT32]: Remove obsolete redefinition of
  function names: sock_write, sock_read and sock_puts.

* crypto/bio/bss_sock.c [WATT32]: For Watt-32 2.2.11 sock_write,
  sock_read and sock_puts are redefined to their private names so
  their names must be undefined first before they can be redefined
  again.

* crypto/bio/bss_file.c (file_fopen) [__DJGPP__]: Make a copy of the
  passed file name and replace the leading dots in the dirname part
  and the basname part of the file name, unless LFN is supported.

* e_os.h [__DJGPP__]: Undefine macro DEVRANDOM_EGD. Neither MS-DOS nor
  FreeDOS provide 'egd' sockets.
  New macro HAS_LFN_SUPPORT checks if underlying file system supports
  long file names or not.
  Include sys/un.h.
  Define WATT32_NO_OLDIES.

* INSTALL.DJGPP: Update URL of WATT-32 library.

Submitted by Juan Manuel Guerrero <juan.guerrero@gmx.de>

RT#4217

Reviewed-by: Andy Polyakov <appro@openssl.org>

e_os.h

diff --git a/e_os.h b/e_os.h
index eaa9396..0166d79 100644
--- a/e_os.h
+++ b/e_os.h
@@ -151,6 +151,7 @@
 #  define writesocket(s,b,n)      send((s),(b),(n),0)
 # elif defined(__DJGPP__)
 #  define WATT32
+#  define WATT32_NO_OLDIES
 #  define get_last_socket_error() errno
 #  define clear_socket_error()    errno=0
 #  define closesocket(s)          close_s(s)
@@ -185,11 +186,14 @@
 #   include <unistd.h>
 #   include <sys/stat.h>
 #   include <sys/socket.h>
+#   include <sys/un.h>
 #   include <tcp.h>
 #   include <netdb.h>
 #   define _setmode setmode
 #   define _O_TEXT O_TEXT
 #   define _O_BINARY O_BINARY
+#   define HAS_LFN_SUPPORT(name)  (pathconf((name), _PC_NAME_MAX) > 12)
+#   undef DEVRANDOM_EGD  /*  Neither MS-DOS nor FreeDOS provide 'egd' sockets.  */
 #   undef DEVRANDOM
 #   define DEVRANDOM "/dev/urandom\x24"
 #  endif                        /* __DJGPP__ */