Added sound effects to the pickups, on the game. Refined the AudioPlayer class to not add the same sound twice.
Enemy leaves a body when dies.
WIP: Partial enemy "inteligence".
Merge branch 'master' of https://github.com/DiogoMuller/cubestein3D

Conflicts:
	src/Cubestein3D/Level.cpp
	src/Cubestein3D/Main.cpp
Enemy now follows player.