Convert each character of the string to the normal form in which it was
	defined in the IPA spec. This would be normal form D, except for the
	voiceless palatar fricative (ç) which should be in normal form C.

	Helper for tokenise_word(string, ..).

def normalise(string):
	"""
	Convert each character of the string to the normal form in which it was
	defined in the IPA spec. This would be normal form D, except for the
	voiceless palatar fricative (ç) which should be in normal form C.

	Helper for tokenise_word(string, ..).
	"""
	string = unicodedata.normalize('NFD', string)

	for char_c in ipa.get_precomposed_chars():
		char_d = unicodedata.normalize('NFD', char_c)
		if char_d in string:
			string = string.replace(char_d, char_c)

	return string