Add kill-rectangle-save to rect.el

[Chitale, Sandip V]

In GNU Emacs 21.3.1 (i386-msvc-nt5.1.2600)
 of 2003-03-27 on buffy
configured using `configure --with-msvc (12.00)'
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: ENU
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: t

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

There is copy-rectangle-to-register but no mechanism to copy
rectangle to kill ring which can be pasted using 

C-x r y

which runs the command yank-rectangle.

However there is no kill-rectangle-save which is along the lines of
kill-ring-save except it applies to rectangle.

Proposed key binding:

C-x r M-w.

Recent input:

Recent messages: