I have improved the phase 4 of final enemy (explosions, new shot, collider).
Merge branch 'DevFinalEnemy' of https://github.com/maxi-jp/project_chandra into DevFinalEnemy

Conflicts:
	IS_XNA_Shooter/IS_XNA_Shooter/IS_XNA_Shooter/GRMng.cs
	IS_XNA_Shooter/IS_XNA_Shooter/IS_XNA_ShooterContent/IS_XNA_ShooterContent.contentproj