5.0 release schedule proposal

[Peter Maydell]

Here's a suggested set of dates for the 5.0 release:

2020-03-17 softfreeze
2020-03-24 hardfreeze/rc0
2020-03-31 rc1
2020-04-07 rc2
2020-04-14 rc3
2020-04-21 release, or rc4
2020-04-28 release if we needed rc4

(I'm at a conference week of 23-27 March, so possibly rc0
might get a little delayed if I'm not able to handle
pullreqs while away, but usually the big rush is for
softfreeze so I think this should be OK.)

NB: Easter is 10th-13th April, so between rc2 and rc3.

Any opinions/suggested tweaks/etc?

Of course if somebody else wants to do this release cycle
they can set the dates :-)

thanks
-- PMM