2020-05-16 updates

Working on balancing.

Still need to add swarm fighters to bona.

When dmg labels were spawned at random around bona the game shortly became unplayable.

Made number of bonas at max 5.

Number of stars spawned is  score/1000 rounded to integer with max at 10.

Some ideas:

- after event X change player weapon, or add new bullet stream

- bonas have to move up and down maybe also

- bonas can't overlap. Need to redo spawning locations.

- make dmg labels permament with the enemy scenes, rewrite the values upon hit and not spawn them with each hit