fixed makefile to compile c and c++ files properly
Added player class to handle playback of files.

	A Player class was created that manages the playback of mp3 files.
	Playback is done in a separate thread such that the user can still
	use the buttons and display while music is played.
	The playback is done using code from
	http://hzqtc.github.io/2012/05/play-mp3-with-libmpg123-and-libao.html