Implemented send song and send artist commands

Implemented the commands for sending the current song name and current
artist name.  The labjack sends first the song name letter by letter,
then sends the artist name letter by letter.  the arduino receives this
data and prints it to the lcd display.   With this version, I have the
song "who says" by john mayer hard coded into the command module, but
changing the strings proves that it works with any song/artist names.