pbm files and elisp manual

[Nick Roberts <nick@nick.uklinux.net>]

Having *almost* installed my changes for gud.el and gdb-ui.el correctly, I've
got the following questions :

1) I've also installed a set of 12 XPM image files in emacs/lisp/toolbar whose 
   names are all prefixed with gud. I see that all the xpm files have a pbm 
   counterpart. I don't know why they are needed (do people really have
   binary displays ?) and presume these are generated from the xpm files.
   Can someone please either install the pbm counterparts for me or explain
   how to do it (whichever is easier) ?

2) I found the elisp manual invaluable in writing gdb-ui.el. Could a section
   for the functions in button.el (e.g define-button-type, insert-text-button
   etc.) be added as these seem to be of general interest ?
 
Nick