This goes a step further than 974959d637b7 and backs out the unreleased
--cache-largefiles option. The same can be achieved with --lfrev heads(pulled()) and
we shouldn't introduce unnecessary command line options.
The revset will be evaluated after the changesets has been pulled, and missing
largefiles from matching revisions will be pulled to the local caches.
This in combination with revsets will make it possible to specify different
strategies for pulling largefiles.
The revset expressions used for this option might be quite complex and will
probably be most useful from scripts or an alias ... but less complicated than
configuring hooks.
After discussion, we've agreed that largefiles for newly pulled heads should
not be cached by default. The use case for this is using largefiles repos
with multiple remote servers (and therefore multiple remote largefiles caches),
where users will be pulling from non-default locations on a regular basis. We
think this use case will be significantly less common than the use case where
all largefiles are stored on the same central server, so the default should be
no caching.
The old behavior can be obtained by passing the --cache-largefiles flag to
pull.
