Safer implementation of the previous change

Medusaling swarms no longer spawn on IO, fully transistion to Archmedusalings at that point. Medusaling when flying over the void will periodically head towards the player to prevent them getting stuck at the edge of the map

Medusaling blinding debuff no longer stacks so applies for a maximum of 5 turns.

Made idle sound quieter.

Make Arch Medusalings the same size as regular ones to avoid occasionally graphics bugs at their current scaling that normal ones don't seem to experience.

Updated for 1.8

Made medusaling idle sound slightly quieter.

Fixed blindness increasing vision range on low light levels.

Lowered Medusaling splash resistance and difficulty dependent slithering dodge cap based on feedback. Still take minimum two grenade launcher grenades to kill and a hard to hit but not as hard.

Fixed definition of Exalted Arch Medusaling that crashed the game if the game tries to spawn them as an exalted pack