Deprecate single segment ns

[frenchy64]

Does not work well with Graalvm: https://github.com/clj-easy/graal-build-time#single-segment-namespaces

Consider java-time.api.

[seancorfield]

When you rename the namespaces, you probably want to rename the group/artifact since right now it's clojure.java-time/clojure.java-time which is both repetitive and a bit misleading (since people might think it's somehow a core/Contrib library).

Then you wouldn't need to keep the old ns at all: folks could have both libs on their classpath and they wouldn't conflict, allowing them to require both and migrate from one to the other piecemeal. That's what I did with HoneySQL.

[frenchy64]

Thanks @seancorfield, added a notice at the top of the readme to attempt to dissuade any association with Clojure. Not going to take further action for now.

[seancorfield]

"This library has no relation Clojure's" -- missing to.

Thanks for adding the clarification.

We use this library quite a bit at work so it's good to see it getting some love, although we're sort of ambivalent about using a wrapper rather than plain interop in many cases (we've already migrated away from both date-clj and clj-time).

[frenchy64]

FWIW this command helped me get 80% of the way to migrating a large codebase.

git grep -l java-time | xargs sed -i '' 's/java-time/java-time.api/g'