Merge of diet branch to main

GAMS/IntExtOpt.gms

data/3deg/protected_areas.txt

data/halfdeg/protected_areas_with_points.txt

data/halfdeg/protected_areas_without_points.txt

data/sims/bioEU.csv

data/sims/bioEU_nopa.csv

data/sims/combined.csv

data/sims/diet_nopa.csv

data/sims/diet_pa.csv

data/sims/diet_singles_with_pa.csv

data/sims/diet_singles_without_pa.csv

data/sims/workshop.csv

src/ac/ed/lurg/ModelConfig.java

src/ac/ed/lurg/ModelMain.java

src/ac/ed/lurg/country/CompositeCountry.java

src/ac/ed/lurg/country/CompositeCountryManager.java

src/ac/ed/lurg/country/CountryAgent.java

src/ac/ed/lurg/country/CountryManager.java

src/ac/ed/lurg/country/GlobalPrice.java

src/ac/ed/lurg/country/SingleCountry.java