Started work on configuration

Added json-minimal library. Added json file.
Merge branch 'configuration' of https://github.com/BSG-TUDelft/Utopolis into configuration
Added societal capital to resources
Game now reads configuration file for structure info
Resource generation will now take into account the number of assigned citizens. More citizens = more resources
Context menu shows the correct resource update interval time (10 seconds at this moment)
Societal capital is properly increased
Merge pull request #128 from BSG-TUDelft/configuration

Merging.