[RFC] kbfiles: an extension to track binary files with less wasted bandwidth

[Andrew Pritchard]

The largefiles rename is done, and the Kiln-specific bits are now split out
into their own meta-extension.  We have moved it out of the old repository into
a more appropriately-named one at
https://developers.kilnhg.com/Repo/Kiln/largefiles/largefiles.  At this point,
there shouldn't be any remaining naming or copyright concerns, so the focus can
be placed on anything that would block largefiles' inclusion in Mercurial's
bundled extensions.