Changed file structure to one folder for resources, added a background to math
Changed size, fixed error in division exercises, deleted unnecessary files
Made some comments, ordered imports
Playlist now works independently of directory, added music, added text file in which names of songs are stored.
Added new folder with audio in it, and the musiclist containing the appropriate name
Merge pull request #19 from Armarillo/playlistChanges

Playlist changes and Math changes