This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
on the installation floppy.
Also pulled the entity definitions for the various sections out
of handbook.sgml and put them in their own file since they are used
both by handbook.sgml (the full version) and boothelp.sgml (the
abridged version).
