pretty big update, balance wise. still Windows only as my iterations are really high right now...

- went through every single boss on deity today, to see if it might be beatable and made some adaptations
- grazing range extended from 100, to 150
- grazing shot power reduced to 2 from 3
- fixed Snowflake, did not fire on Easy/Normal since last update
- altered shot patterns on final boss, reduced randomness. seems better
- turret upgrades have been buffed, more shields/armor, fortify also increases shot rate a bit, protect increases firepower
- turrets are stronger on higher difficulty levels
- using phase shift makes the nuke timer go up again, 1 sec phasing -> 1 sec longer wait for nuke
- final scene, fixed a position jump in mother ship