[c-lightning] Feature freeze in preparation for 0.6?

[Rusty Russell]

Hi all,

        I want to start a feature freeze, to ensure we can focus on
bugfixing and API polishing; bugs are an obvious problem, but any API
we have in 0.6 is going to need to be maintained at least until 0.8.

Please list any new features/changes you want to complete before 0.6
(not counting bug fixes). I've added two already:

1. The proposed gossip spec enhancements.
   I've implemented it, just got to test it.  It's important for other
   peers as it greatly reduces their bandwidth requirements, and I'd
   prefer not to have them avoid our peers because we spam them.

2. Adding an SHA256 tag to the gossip store.
   The gossip store is append-only, and not synced: a checksum allows us
   to ensure it has been saved correctly.  This change will require
   the store to be re-synced, so it's best to do this now before the
   network grows too large.

I've added these to GH, and am working through the existing issues
tagging them v0.6 (or closing) as appropriate.

Thanks!
Rusty.