Added a new currency: gold. Gold is automatically collected from your villagers and is used to pay for building maintenance and building upgrades.

Added two new buildings. The first one is the engineers workshop. The engineers workshop allows you to pay gold to upgrade current buildings.
The second building is fishing dock. The fishing dock adds a way to make use of the water and constant food generation.

Changelog:
Decreased the time for raiders to appear from 4 years to 3 years.
Made guard tower have gold upkeep. Each guard tower cost 16 gold to upkeep each month.
Increased the granary storage capacity from 100 food to 200 food.

Bugfixes:
Fixed issue where villagers would not eat food from granary even if there was enough available.
Fixed issue where having just enough resources to build a building would freeze the villagers.
Loading a save file should no longer make player able to build on existing townhall building.
New villagers should now automatically be assigned to work if there is work available.
Resource storage and granary now updates their resource and food count automatically.