New Stage Added!

- Added Stage 4 to the game
- Stage 4 is now accessible in practice mode.

Adjustments
- Reduced the amount needed to buy alt colors to 1000 data per color.
- Reduced the increment for buying credits from 1000 increase to a 500 increase.
- Added a function where some bosses give off small amounts of hyper energy when reaching a certain HP threshold.

Bug Fixes
- Fixed a bug where Rouge Delta wouldn't leave it's temporary speed/invul mode when using it's special weapon, keeping the color blue and increased ship speed.
- Fixed alt colors not displaying properly when the ship spawns/during cutscenes.
- Fixed a bug where the continue screen wouldn't show if the player ship is destroyed.