Added config loading capability and implemented it for EM and IO.
Moved (I think) all configuration constants into the config file.
Added in config defaults so tests work. And added config test.
Updated travis.yml to get google's gcfg config file package.
Merged master back in to pick up recent changes.
Merge branch 'master' into config

Conflicts:
	entitymanager/entitymanager_test.go
Changed EM to access config directly.
Changed brain and IO to access config directly.
All modules changed to access config directly. Config now only defined in one place.
Updated LM tests to be compatible with new config model.
Made brain UTs compatible with new config model.
Made config UTs compatible with new config model.
Made creature UTs compatible with new config model
Updated EM tests to be compatible with new config model.
Made food tests compatible with new config model.
Made genetics tests compatible with new config model.
Made graphics tests compatible with new config model.
Made graphcis FV test compatible with new config model.
Removed unnecessary config loads in list_test
Merge branch 'config'

Conflicts:
	graphics/interpreter_test.go
	iomanager/iomanager.go
	iomanager/sdl/graphics_fv_test.go
	main.go