New option - Keep multiple spaces

As I wrote in a recent message, I was able to compile and run the latest
CVS source code on Debian Stable.  I was delighted to find a new option
(off by default) in Edit > Preferences:

  General > Keep multiple spaces

I tested it out and found that it works fine for 2 or more spaces:

  Between words.
  Between the start of the line and the first word.
  From the last word to the end of a line (actually to a </p>).

In these cases, it follows the algorithm suggested last month by Greg
Noel, and which I described on 4 September:

  Between words or at the end of a line, Mozilla Composer's algorithm
  is:

  n typed or pasted spaces are converted to n-1 non-breaking spaces
  followed by 1 space.

However the current implementation does not work in two circumstances:
where there is a single space either at the start of the line or at the
end.  In these cases Amaya currently inserts a single ordinary space.
This appears fine in Amaya, but it does not, and as far as I know should
not, produce a visible space in a browser or editor such as Mozilla.  I
think the correct response should be to use a single non-breaking space.

I don't think we discussed a single space at the end of a line.  The
spaces at the end of line issue is pretty low key, but a single space at
the start is important.

Irene and Team, thanks very much for this new feature!

  - Robin