This record of changes may help developers to understand how to modify
or debug the code.  It helped me as I debugged the Dog app.

First, I followed instructions in the README, as follows. 

I copied ../templates/is.php to ./App.php and changed it to be like a
App name table.

Then I modified Makefile with APP=App and called 'make' in ops/is to
create the rest of these files in ops/is/App.

Then I made sure mysql could run under root, and under public_user for
db tv table App (isApp.db helped).

Then I got the record of old submissions into dog.db.txt and modified
that to dog.20211015.sql and sourced that in mysql to upload the data
into the column tv.App.name.

Then I used ./index.php to test it can create, read, and delete items.
No point in update yet since what do I need to do, fix the spelling of
a name?

isApp.php provides a REST-ish API on HTTP requests with (usually) JSON
data in the HTTP message body, for example for searches. 

Then I tried to do a search, "SELECT * from tv.App" (e.g., WHERE
id>0), but it fails to retrieve anything or show anything.  So track
the Search code process through parallel to the Read process which is
known to work.

An operation skips around among so many levels.  Update is more
complex; Create, Read, Delete are marginally simpler; so let's look at
Search, with its stack of forms, functions, and places, as follows:

  in version 2.0, index.php had a hook to hang UI on, isSearchDiv, 
    and called isApp.js:addSearch() to put UI there, including a search form,
    but now index.php puts BuildSearchForm() into ControlArea.
  user calls for search in the UI search form
  form onsubmit calls is_App_search()
  isApp.js:is_App_search() prepares url, json, and onload callback function
    for generic isSearch() to use, then calls isSearch()
  isapi.js:isSearch() takes prepared details and calls xhr.send()
    xhr.send does its async work triggering myonload later, more on that below.
    xhr.send() on the client disappears into the ether then
         reconnects with us again on the server in isApp.php
  isApp.php on the server provides a REST-ish remote interface for search &c.
    it gets the http request, parses out the request type, the URL, any json input,
    handles all requests.  Checks error conditions, website user privileges, builds SQL for
    PUT (update), POST (create), DELETE (delete), GET (read or search)
    calls sql, packages the results, returns them.
  after xhr.send gets results from server, it calls myonload.
  isApp.js:myonload() defined within is_App_search()
    processes returned responseText (json) using gotPut()
  isApp.js:gotPut(res,appNameList) puts results into appNameList

Other locations search appears:

  isapi.js:is(op...) checks whether op=='search'
    and calls isSearch(), but this is never used.
    the URL no longer contains op=S|C|R|U|D;
    instead we use HTTP request type to decide what kind of request it is.
  
  isApp.db:elif [ $1 == "search" ]      explains how to do search sql manually