Update 0.6.6

- Added new building "Iron Quarry". Iron ore drop rate is increased by 35%, everything else is decreased by 90%. Also mining priorities are added for quarries.
- Peasant-archers will use towers after using move/attack command in the area near tower (in the range lower than archer's attack range). Each tower can be used only by one archer. Peasants will use towers only while "called to arms".
- Peasants will not sort/drop items after calling to arms.
- Fixed a bug where shield's activation reduced speed too much.
- Speed reduction during bow attack increased from 50% to 67%.
- Fixed a bug where equipment on ground saved wrong (it has negative durability after loading).
- Fixed minor issues in wild farm generation.