update mingw info

  * Visual C++

  * Borland C

  * GNU C (Mingw32 or Cygwin)

  * GNU C (MinGW or Cygwin)

 If you want to compile in the assembly language routines with Visual C++ then

 you will need an assembler. This is worth doing because it will result in

 * Run make:

   > make -f bcb.mak

 GNU C (Mingw32)

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 To build OpenSSL, you need the Mingw32 package and GNU make.

 GNU C (MinGW)

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 * Compiler installation:

   Mingw32 is available from <ftp://ftp.xraylith.wisc.edu/pub/khan/

   gnu-win32/mingw32/gcc-2.95.2/gcc-2.95.2-msvcrt.exe>. Extract it

   to a directory such as C:\gcc-2.95.2 and add c:\gcc-2.95.2\bin to

   the PATH environment variable in "System Properties"; or edit and

   run C:\gcc-2.95.2\mingw32.bat to set the PATH.

   MinGW is available from http://www.mingw.org. Run the installer and

   set the MinGW \bin directory to the PATH in "System Properties" or

   autoexec.bat.

 * Compile OpenSSL:

 Consequently, a make of OpenSSL with Cygwin is closer to a GNU

 bash environment such as Linux than to other W32 makes which are

 based on a single makefile approach. Cygwin implements Posix/Unix

 calls through cygwin1.dll, and is contrasted to Mingw32 which links

 calls through cygwin1.dll, and is contrasted to MingW which links

 dynamically to msvcrt.dll or crtdll.dll.

 To build OpenSSL using Cygwin: