1) Reviewed fish & z-fish stats
2) Made fishing with rods work chatch from the spawned fish
3) Added a good rod, added code to handle it, added it to some spawn
lists in the item_groups
4) Made a catch_monster function that will choose a random monster from a list
to catch. Catched monsters die without leaving a message or corpse,
since the corpse in indipendently spawned and has started to rot
depending on fishing duration.