Trying to add a .gitignore file.
Reverting previous commit. That file must be kept local.
Started SoundHandler class construction.
SoundHandler interface, first version.
Avances con la implementación del SoundHandler.

Hubo algunos añadidos en la interfaz, y otros cambios menores.
SoundHandler implementation finished.

All functions of the module have been implemented,
TESTING is due now.
Also some files from other modules were corrected
for proper inclusion of libraries.
Testing of new SoundHandler module (DONE).
Everything seems to be alright. Individual playlists handling functions
still need to be checked in depth though.