Implement Basic Health/Damage System

[Achie72]

Create a Crude Health System to the game. Entities should have a health and should be able to damage others based on conditions.

• Player should be able to hurt enemies with jumping on their head.
• Player should be able to harm enemies with the ground pound ability.
• Graphical Indicator for enemies being hurt.
• Sound indicator for enemeis being hurt.
• Enemies should be able to harm the player upon collision.
• Graphical Indicator for Player being hurt.
• Sound indicator for the Player being damaged.
• Game Over screen upon the player losing all health.