function compareFixesByRange(a, b) {
	return a.range[0] - b.range[0] || a.range[1] - b.range[1];
}
Compares items in a fixes array by range.
@param {Fix} a The first message.
@param {Fix} b The second message.
@returns {number} -1 if a comes before b, 1 if a comes after b, 0 if equal.
@private