Hello other org mode aficionados! (I apologize for the errant email I 
send a minute ago. )

I have created a (possible) patch to the export (ox.el and other 
ox-XXX.el) files that allow for "source code" and "example" blocks to 
have line numbers starting at an arbitrary number. Before the 
(wonderful) ox redesign I used to have advice around some functions. I 
hadn't needed this functionality for a while, but now that I did I 
thought I would share.


The code is written with the following design:

-n   is the same as -n 1 : The functionality is unchanged
+n   is the same as +n 1 :  The functionality is unchanged

-n X   will "reset" and start new code block starting at line X
+n X   will "add" X to the last line of the block before.


========
example:
* Heading 1

   * ~-n 10~
     #+BEGIN_SRC emacs-lisp -n 10
       (save-excursion             ;; This is line 10
          (goto-char (point-min))) ;; 11
     #+END_SRC
   * ~-n~
     #+BEGIN_SRC emacs-lisp -n
       (save-excursion           ;; line 1
          (goto-char (point-min))) ;; line 2
     #+END_SRC
   * ~+n 155~
     #+BEGIN_SRC emacs-lisp +n 155
       (save-excursion            ;; line 157
          (goto-char (point-min))) ;; line 158
     #+END_SRC

Gives the following "Text - ascii output"


1 Heading 1
===========

   * `-n 10'
     ,----
     | 10  (save-excursion             ;; This is line 10
     | 11     (goto-char (point-min))) ;; 11
     `----
   * `-n'
     ,----
     | 1  (save-excursion           ;; line 1
     | 2     (goto-char (point-min))) ;; line 2
     `----
   * `+n 155'
     ,----
     | 157  (save-excursion            ;; line 157
     | 158     (goto-char (point-min))) ;; line 158
     `----


I have tested the code (using make test) and generated (hand verified) 
the LaTeX and HTML output. ODT has an issue already with +n in that each 
code block starts at line 1. (I did not address that).


I have included the git format patch output.

This is a fairly small set of changes, but I do assign the Copyright to 
the Free Software Foundation.


Thanks,
;-b