Draft of 8.5 release notes

[John Clements]

Here's a draft of the 8.5 release notes, let me know about additional items that should appear, items that are misleading or wrong, or things that are here but shouldn't appear.

Or ordering! We can talk about that, too…


* Racket includes a new flag that automatically stores a compiled
version of the code being run.

* Error-message Realms allow languages to adapt and rewrite error
messages to make sense in a particular context.

* Nonprivileged users can control package installation scope using an
"other-version" directory in the addon-dir.

* Users of platforms without a native back-end can run Racket programs
at acceptable speed using the improved pb implementation.

* DrRacket's new 'Reopen Closed Tab' file menu item will open previously
closed tabs.

* Typed Racket has support for the `xml` library; use `typed/xml`.

* Rackunit reports source locations for failed test cases in the
Typed Racket language.

* Plot has violin plots and improved box-and-whisker plots.

* The release includes many other repairs and changes!