Regarding the superblock thing, I think that the easiest would be to force one block (let's say block 122000) to have the desired difficulty and then return to normal. At current rates, I expect it would take about 30 mins (expected time) to solve the world-record block. Less if we are lucky, more if we aren't. This would require everyone to update to the new client but nothing else would need to be changed.
There will be a delay on transactions, but only for less than half an hour. Think of it as "expected downtime". We could make that block have a reward of 600 to accomodate for the extra difficulty.

What do you say?

Fixed a bug in b15 reported by github user HenryHu.  This doesn't seem to affect the Linux version, but I wonder if it's related to the hang on Windows.  The fix has been pushed to git in https://github.com/dave-andersen/fastrie/commit/79e21cecb9bea07caac30c6a6b46735f558faee8

(It's a one-line fix that should not mess up Gatra's current effort at porting to stratum)

I've put a temporary alpha test binary in http[Suspicious link removed]

if someone with windows wants to see if that one actually works or not.  It probably doesn't, but it's worth checking.

Thanks to HenryHu for the report and precise identification of the bug!

(If anyone tests it and notices that this actually fixes a real bug on Linux, LMK and I'll push out a quick b16 build)