Nick's implemented score system
Added Background class and method
Faded Background
Fixed hit detection
changed explosion icon
earerge branch 'master' of https://github.com/YanaSlavcheva/SoftUni-Java-Teamwork-TATOOINE

Conflicts:
	bin/spaceinvaders/Board.class
fixed bombs and shot colors and sizes
Hit Detection fixes
fix health
Finalized HP and Hit detection
Finalized HP