Branching 1.6.x this week

[second verse, same as the first...]

Alright folks, we're branching 1.6.x this week. Here's the schedule of events:

Nov. 12, ~1700 UTC: Create 1.6.x branch from current trunk.
Nov. 12, sometime in the evening: Roll 1.6.0-pre1 and get some sigs.
Nov. 13: release 1.6.0-pre1

I know that we've still got some stuff in the TODO file, but it feels like it
isn't anything which can't happen on the branch (glasser, I haven't forgotten
about the FSFS stuff. :) ) Also, trunk is generally looking more stable now,
and by branching, we can work on stabilizing the branch independent of any
destabilizations going on in trunk.

I propose that the -preN releases don't require the full signature complement,
and that we release them *even with known* issues, while enumerating those
issues as part of the release. I also propose that we use the looser voting
guidelines while still doing -preN releases to aid code mobility into the branch
(while still getting a second set of eyes on it). These changes mirror what we
did early in the 1.5.x release cycle.

Objections?

-Hyrum