Rebuild the track listing as an interactive grid

First, we add an SQL statement to alter the TRACKS table to add a
column to store the address of the audio file.

We also update the showTracks( ) function to change the DOM development
of the track article element.    We add update and delete buttons for
each track.    We use a contenteditable attribute on the data elements
to allow for updates.

Note how the article holds the trackid data for each row.  After the
DOM is built in showTracks, we add click event listeners for the
buttons.   Now how we are able to retreive the trackids relative to
each track using the parent( ) jQuery function.
Getting the context data

Add the parent information of the track to the parent structure of the
DOM for easy access.
Update the client record

Gather data to change or delete the appropriate track record in the
local Javascript data object.    Then refresh the view by calling
showTracks( ) recursively.