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.
Errors in document processing are almost never passed back to `make'.
Removed the requirement for having an obj directory. fig.2.3.n
previously had to live in obj/.