Broadcasting diagrams

[Jordi Gutiérrez Hermoso]

I made some diagrams for the broadcasting section in the new chapter:

    http://jordi.platinum.linux.pl/piccies/bcast-ApTimesB.png
    http://jordi.platinum.linux.pl/piccies/bcast-xpy.png
    http://jordi.platinum.linux.pl/piccies/bcast-ymyp.png

Corresponding Dia source:

    http://jordi.platinum.linux.pl/piccies/bcast-ApTimesB.dia
    http://jordi.platinum.linux.pl/piccies/bcast-xpy.dia
    http://jordi.platinum.linux.pl/piccies/bcast-ymyp.dia

I can't figure out how to stick them into the manual, though. I also
plan on making some corresponding ASCII drawing for the .txt pictures
that TeXinfo can use. Can someone help me figure out how to integrate
these with the documentation build system? Should the "generated"
.png, .eps, and .pdf drawings go into Mercurial? I suppose they should
be part of the build system, but I don't know if it's ok to add dia as
a build-dep to Octave. That seems a little heavy-handed. Dia can be
run in batch mode, e.g. the command

    dia bcast-ymyp.dia --export bcast-ymyp.jpg

converts the dia diagram to jpg.

TIA,
- Jordi G. H.