Slight changes/improvements

- Fishing now reduces size of River by 2 instead of 5. - Hunting now gives 1 Deer and 2 Mushroom. - Added Mushroom find chances to Forest, Grasslands, Farmlands, Pasture, Farm. - Added extra 1 Deer chance to Hunt job. - Added extra 5 Fish chance to Fish job. These changes aim to help with early survival while still keeping hunting/gathering an unreliable food source. - Pasture and Farm jobs now output products proportional to their progress when Winter arrives instead of outright cancelling the job. If a Farmer is done 30% when Winter arrives, you will get 30% of products. - Snake Nests can no longer raid. - You can now safely retreat from a battle if you are the attacker. You would previously get happiness penalty.