EMP Bombs

[Rybadour]

Develop a new attack the player can use.

• The Player holds x to charge an EMP bomb
• When the bomb is charged to half it's maximum and released it destroys all enemy bullets on the screen
• When the bomb is charged to full and released it destroys all enemies and enemy bullets.

The bomb should do enough damage to kill most enemies, but it shouldn't simply kill them. This is because the boss should not be killed outright by the EMP bomb but only damaged a bit.

[hlynka-a]

Just uploaded branch for this. Charge bomb with shift key. Release bomb with x key. If half full, bomb will destroy all bullets on screen. If full, bomb will destroy all bullets and severely damage all enemies on screen.
Let me know if it has to be fixed.