Order of attributes is inverted on each save

[Bug Importer]

Inkscape-version 0.41
OS: MS Windows XP Pro, SP2
-------------------

When saving an SVG-file in Inkscape the order in the
file is different every time.
This makes it difficult to look at changelogs on a
SVN-file in a file revision system, since a lot of
lines has moved for no visible reason.

I tried to reproduce the case in two files (attached to
bug).
This is what I did.
1) created a SVG-file and saved it.
2) Closed inkscape and opened the file with double-click.
3) Moved the blue rectangle.
4) Saved the file and closed inkscape
5) Made a copy ("before move")
6) Opened the same file with double-click.
7) moved the blue rectangle i little bit.
8) Saved the file and closed inkscape
9) Made a copy ("after move")

then making a diff between "before move" and "after
move" reveals that lots of rows has been swapped.

----- Example from "before move" ----
   sodipodi:docname="test.svg"
   sodipodi:docbase="C:\DOCUME~1\Albin\Desktop"
   inkscape:version="0.40+cvs"
   sodipodi:version="0.32"
   id="svg2"
   height="297mm"
   width="210mm">
---------------
----- The same example from "after move" ----
   width="210mm"
   height="297mm"
   id="svg2"
   sodipodi:version="0.32"
   inkscape:version="0.40+cvs"
   sodipodi:docbase="C:\DOCUME~1\Albin\Desktop"
   sodipodi:docname="test.svg">
---------------

// Albin Sunnanbo (albin [at] sunnanbo [dot] com )

[Buliabyak-users (buliabyak-users)]

In XML, the order of attributes is not significant, so
strictly speaking it's not a bug. But it's still interesting
to find out why this happens, and fix if possible. Maybe
attributes are added by prepend when read but written via a
forward loop, hence the order is inversed.

[Albinsunnanbo (albinsunnanbo)]

I can not figure out how to attach my other file, but I
suppose that the example above is suficcient to phenomena.

I looked through the rest of my diff and it looks like it's
always a strict inversion of the order of the attributes.

To further support the idéa of inversion I repeated streps
(6) through (8) and copied the file to "third.svg".
Now when I diff "before move" against "third" all attributes
are back "in order" and only the "x" and "y" attributes of
the <rect> and the inkscape:cy attribute of
<sodipodi:namedview> has changed.

[Mental-users (mental-users)]

Attaching a patch which should remedy the attribute order
reversal.

[Mental-users (mental-users)]

Please test.

[Kees Cook (kees)]

Looks/acts fine for me. Committed.