editors/vim: Update to 8.2.4669, add x11 support, drop Athena

Vim no longer includes the Athena (Xaw) frontend, so drop the
athena flavor.

As requested by many (and based on a patch from scf), restore the x11
flavor. The x11 flavor is a bit odd; it doesn't actually include an X
GUI. As a result, when Vim got flavorized I dropped it as I thought
it was vestigial. What the x11 flavor actually provides is support for
some X interaction (mainly xclipboard), and is highly useful to people
who run console Vim within X.

The outcry was pretty swift, and I'd like to thank all the people who
took the time to email me about it, and especially scf who provided
the bulk of this patch.

I'm going to MFH this due to the athena build failure.

(cherry picked from commit de02b1a9d209f0b6727e63848bc58c9b4ef1c064)