v1.4.0

• function/stdlib: The string functions that partition strings into individual characters (grapheme clusters) now use the appropriate segmentation rules from Unicode 12.0.0, while previous versions used Unicode 9.0.0.
• function/stdlib: New functions Replace and RegexReplace for matching and replacing sequences of characters in a given string with another given string. (#45)
• function/stdlib: The function Substr will now produce a zero-length string when given a length of zero. Previously it was incorrectly returning the remainder of the string after the given offset. (#48)
• function/stdlib: The Floor and Ceil functions will now return an infinity if given an infinity, rather than returning the maximum/minimum integer value. (#51)
• cty: Convenience methods for constructing path index steps from normal Go int and string values. (#50)