Added audio recorder functionality writing recorder audio to external
file.  Only one external file can be written and new recordings will
replace old ones.  This is the file that is played when the
Added audio recorder functionality that writes the audio to an external
file.  Only one audio file can be written and new versions will
overwrite the previous.  This is the file that is played when the
"Play" button is pressed.  If there is no file to play, a message is
displayed and nothing happens.  the "Record" button is disabled during
playback and the "Play" button is disabled during recording.  When the
"Record" Button is pressed it becomes the "Stop Recording" button and
when the "Play" button is pressed it becomes the "Stop Playback" button.