Fixed a bug where sinkholes could be "destroyed" (i.e. Bearger stomping nearby) but still exist, and could no longer be repaired until the server restarts.

Increased Normal shovel repair time to 96 seconds (from 48).
Increased Better shovel repair time to 240 seconds (from 120).

Increased Normal shovel loot chance to 4% (from 2%).
Increased Better shovel loot chance to 10% (from 5%).

Added Weak setting for shovel repair time and shovel loot chance, which use the old Normal values.

Fixed new sinkholes being unable to be dug until the server restarts.