Add encapsulated deferred-length strings

The primary benefit of encapsulating deferred-length character variables is to facilitate defining ragged-edged arrays of variable-length strings. This release also adds a method for converting a delimited list of strings into an array of substrings.

What's Changed

• Feature: encapsulate deferred-length string by @rouson in #38

Full Changelog: 3.4.1...3.5.0