Enemy Projectiles, Restructure and SegFault

-restructured enemy projectiles: include enemyProjectiles.h, which in
turn includes enemyProjHandler.h
-testing stage: segfault occurs on trying to get nextFrame of
projectiles
-somehow, pointer of value 0 is pushed into the vector. I'm not sure
why.
-the line to test is 440 in Source.cpp - it spawns an enemy proj 60
frames into the start of the game (which is when it crashes, currently)
-line 440 is commented out - uncomment it to test and debug