As mentioned in the comment, it appears texinfo 7.0.3 is inconsistent
in converting apostrophes in the source to
right_single_quotation_mark. Leave the code commented out for now.
Update the regexps so we can find the things we need when the html
files were generated by texinfo 7.0.3. This needs to be done in a
better way, but for now, let's just get things working.
Currently, the verification says:
```
Verifying html index
Warning: Number of HTML entries (2995) does not text entries (3070)
Warning: 2 HTML entries not in text entries: "Euler's number" "Introduction to Maxima's Database"
Warning: 77 Text entries not in HTML entries: "Introduction to Maxima’s Database" "!" "%union <1>" "*" "-" "/" "<=" ">" ">=" "Euler’s number" "]" "^" "bf_find_root" "bf_find_root <1>" "bfpsi0" "c" "c2cos" "complex" "covect" "declare_index_properties <1>"... plus 57 more
```
Don't understand issue with "Euler's number". Something about the apostrophe?
We weren't closing the file so not everything was being flushed to the
log file. Using `with-open-file` guarantees we'll close the file and
flush everything to the log file.
This makes the HTML links show up before the entry. Previously, it
would show up after, which doesn't look so good. Now the browser
starts at the definition instead of at the paragraph after the
definition.
Previously these @vrindex entries were only available for info files.
However, it's useful to have them for the html files so that every
text topic can also be found in html.
With this change, it looks like the set of html topics and text topics
is identical.