Monte Goulding

@livecodeali have gone ahead with the above and added docs & notes

GitHub apparently lets me push to your repo @runrevmark so I'll do that and we can keep this PR open.

@peter-b it appears `std::enable_if` is an issue. Any recommendations?

This looks interesting @livecodeali

We probably want to add some extra format codes at some point. After we discuss this PR I will either add them to this or add an enhancement report for...

Marked as WIP until we have time to look at using the ICU date formatter

wouldn't it be nice to just use the ICU date formatter and parser rather than our own? Or will we need our own regardless for backwards compatibility and need a...

@runrevmark should I split this up so we can merge what parts we want now and keep thinking about the rest or are there some changes I can make (beyond...

Round trip to disk tests will merge up from [this PR](https://github.com/livecode/livecode/pull/7196) so we may want to merge that in and up before reviewing this. They pass locally though.

Too slow on long scripts so WIP