Version Control With Subversion Source

(do_history): Moron (mo'-rahn): [1, noun] cmpilato, coding without
noticing his logic cases are backwards. Show "<ID>" in the column
header when 'show_ids' is *true*, not false.

* subversion/doc/book/book/ch08.xml
Correct (hopefully without breaking) the 'svnlook history' example.
Well, I mean, technically it was correct before, but now correct in
light of the corrected code (which was *not* correct before, but is
correct now).