- build the global .png files with a recent svn build:

    gracket-text mk-img.rkt

  This will dump some png files in the current directory. Put them in
  some global place on the server

- to build a script for a particular page, do this:

   gracket-text build-graph.rkt -l http://drdr.racket-lang.org/~a/collects/path/to/file.scm \
                            --image-loc /static/data/graph-images/  \
                            file_scm.timing \
                            file_scm_png_file_prefix \
                            output.html

   The -l flag is optional, without it clicking on the images won't go
   anywhere; with it, clicking will go to the corresponding revision.
   The --image-loc flag gives a url path to the directory containing
   the images from the mk-img.rkt setp.  The other three args are the
   timing data file, a prefix for the png files that generated for the
   graphs, and the output html (which is a <div> ... </div>).