+ let the user know if they can afford to warp
+ added better response for when you overlap a button
* fixed collisions between asteroids
* fixed collisions between enemy bullets and asteroids
* fixed asteroid velocity when shot
* fixed random deaths after playing a while
* fixed damage when asteroids collide with themselves
* fixed health resetting to zero when you get 75+ salvage
* fixed fading to upgrade menu
* fixed salvage not carrying over to the overview tab