README files for Windows platforms

[Rik]

12/30/10

The list of README files which need to be updated before the 3.4 release is
up on the wiki at http://wiki.octave.org/wiki.pl?UpdateREADMEList.  Ben and
company have been doing great work on creating the README.MacOS file and so
we can turn to the Windows files.  There are 4 files:

README.Windows
README.Cygwin
README.MSVC
INSTALL.Windows

README.Windows is the master and merely points out to README.Cygwin and
README.MSVC.  README.Cygwin and README.MSVC need someone who uses these
platforms to review the instructions.  For example, README.MSVC refers to
CVS versions of the code, but of course the preference is for Mercurial
now.  INSTALL.Windows is marked at the top of the file as being out of date
and is not distributed in tarballs according to Makefile.am.  I propose to
delete it.  Finally, does someone (Tatsuro?) want to contribute a
README.MinGW?  I don't mind editing it once the instructions are there, but
I don't use Windows platforms and can't create that file myself.

Cheers,
Rik