[scribus] [1.4.0] autosave file exists

[Peter Nermander]

> The delta system is similar to the undo system except each delta
> is a separate file listing just the changes, like a patch file in Unix
> or Linux. That saves disk space compared to full copies
> (autosave) and does not clutter up the sla file with undo
> information. So the delta system is worth considering.

Many revision systems (if not all) use the same approach. So I don't
think it is a good idea to force Scribus users into using a specific
revision control system.

A better idea would be to make Scribus able to use any revision
control system, or you might say "any file retrieval system".

I think what would be needed for each file retrieval system is set of
commands for getting a list of files, changing "directory", getting a
file (including a specific version of the file), putting a file etc.

Scribus could be supplied with command setups for the most common
revision control systems (rcs, svn etc)

LyX for example has support for rcs I think (at least it did years ago
when I was working with it).

/Peter