Make sure that Configure will defined DSO_WIN32 for the Win32 targets.  I feel a bit unsure if this should really be done for Mingw32 and CygWin32

- Make sure PCURSORINFO is defined even on systems that do not provide it.
- Change the reference to Peter Gutmann's paper.
- Make sure we don't walk the whole heap lists for performance reasons.
  Jeffrey Altman suggests following Peter Gutmann's advice to keep it
  to 50 heap entries per heap list.

Add case of using select() and blocking I/O with
BIOs and why you shouldn't (thanks Bodo!).

behaviour that SSL_read may result in SSL_ERROR_WANT_READ.

tests.  This was required to not get mysterious errors when they
wouldn't quite want to work.

libdl just as linux-elf...

platforms list is clarified (it's however not quite followed in the
RSAREF case...).

RSAREF is also checked now.

from the given target.  Fixed, I hope.

accordingly.

Perhaps we should make rewrites the default thing to do?

the OpenSSL commands x50 and req work better on a EBCDIC system.

Incomplete and possibly inaccurate. Hope somone is
checking these :-)