Return the given string with all known common substitutes replaced with
	their IPA-compliant counterparts.

def replace_substitutes(string):
	"""
	Return the given string with all known common substitutes replaced with
	their IPA-compliant counterparts.
	"""
	for non_ipa, ipa in chart.replacements.items():
		string = string.replace(non_ipa, ipa)

	return string