sombrero default argument (matlab compatibility)

[Andreas Weber]

Dear maintainers,

Changeset befb99c0c72f
(http://hg.savannah.gnu.org/hgweb/octave/rev/befb99c0c72f) makes uses of
default arguments which are incompatible with matlab. I would like to
undo this

-function [x, y, z] = sombrero (n = 41)
+function [x, y, z] = sombrero (n)
+
+  if (nargin == 0)
+    n = 41;
+  endif

to be able to run sombrero in matlab to compare plots.

Any hints or pitfalls I'm not aware off?

Andy