<DE2 Database> Added loadSongsFromSD function

This function will read all songs in .wav format from SD and write it in
a file, with a specific format.
Songs are going to be stored with the following text format:
1 SONG.WAV
2 ANOTHERSONG.WAV
3 SONG4.WAV
etc.
<DE2 Database> Fixed some bugs in loadSongsFromSD

works fine now. we can open the TXT file and see all the wav files :]
Merge branch 'master' of https://github.com/Ilikecattle/EECE381Module2
<DE2> Database

Modified loadSongsFromSD: load all WAV files from SD, create a SONGS.TXT
and load all songs to DB.
<DE2 Database>

Function modified:
- initPlaylist() now needs a char* listname as an argument.
Function added:
- loadListsFromSD() : loads all PLSTxx.TXT file from sdcard, writes all
list & its ID info to LISTS.TXT, and adds all playlist to database.
- openFileFromSD() : opens a file and handles all error
making this as functions since many functions need to open file and
handle errors (reusability).
- getListNameFromListFile() : given a PLST1.TXT or any playlist text
file, read the first line of that file to retrieve the list name. use
this to store playlist to DB.

Note:
Playlist is used to be stored as LISTxx.TXT, but I changed to
PLSTxx.TXT. This way, LISTS.TXT (text file that consists playlists and
their IDs) will not be considered as a playlist.
Hope it make sense =]
<DE2> Playlist, Song, Database
Playlist: change to use setListName in the constructor
Song: add setSongName and change to use setSongName in constructor
Database: add define SONGS.TXT
<DE2> Database, Command, Queue
Added functionaly to add a playlist to database with known id