bugfixes

you cant inspect anything when the game is paused

fixed a bug where selling obstacles could invalidate the path

Basic turret:

- Place cost: 280 >> 320

- The basic turret will lose 1 range at all levels past the place one.

- Upgrades will set range to 5, 6, 7, and 8.5

Gunner turret:

- Third upgrade damage: 4 >> 6

- Third upgrade cost: 3100 >> 2900

- Final upgrade damage: 10 >> 12

- Final upgrade range: 7 >> 8

- Final upgrade cost: 11500 >> 10500