New food mechanics

In the old system, units would eat everything they can in the order it is available in the Tavern till they get to 90% satiety. This had several drawbacks:

• It would look odd to see units consume both Ale and Cider, or Fish and Sausage.
• Sometimes units would overeat and waste the food (e.g. unit ate to 80% and then another 60% sausage, resulting in 40% going to waste)
• Attempts at food management micro distracted from the game

Starting from r13944 new rules are in effect: each visiting unit will want to eat three dishes – meat, bread, drink. Meat can be sausages or fish, bread is always bread, drinks can be cider or ale. Exact choice is made randomly upon availability. New satiety values are:

• Meat – 35% 
• Bread – 25% 
• Drink – 15% 

For each 2 dishes combo unit gets an additional 10% satiety. Result is that in the full Tavern a newly arrived hungry unit (satiety <10%) will eat 35%+10%+25%+10%+15% = 95% which will restore them to full satiety.

Thus, more kinds of food could be added without making them look superfluous (as long as they go into one of the three categories) and the combo bonus will incentivize player to maintain variety of foods in the Tavern 

In early campaign missions not all foods are available, so units will not eat up to their fullest, but this is not a huge problem, they will just return to eat sooner. In later missions (or in missions without waterbodies) one is expected to produce meat sausages to keep the units well fed.

Further work includes reworking UI to be representative of the new mechanics (sort and group foods). Slight tweaking of food values may also be needed.