BonusCommerceModifier for Buildings 2016-10-05

This modcomp allows to modify the output of beakers, gold, culture and espionage of buildings relatively by certain resources, similiar to the already existing BonusYieldModifiers, that does this for food, production and commerce. All changes in the code are marked with "BCM". As examples the market, grocer and bank have their gold output increase modified by some resources.

Many thanks to Afforess for showing me how things had to be done.

Forum entry for this modcomp: http://forums.civfanatics.com/showthread.php?t=341521