[phobos] Time to get ready for the next release

[Don Clugston]

It's now been two months since the last release, and there have been
huge compiler improvements.
Note also that there were a couple of very bad regressions in 2.052,
so I think we really need a release ASAP.
We've now achieved minimal stability again (all green on the auto-tester).

Here's the things which are blockers for the next release:

>From the compiler side:
* struct destruction of temporaries (seems like we have a chance of
fixing this soon)
* fixing the regressions from my CTFE/const folding changes (Fixes are
here: https://github.com/D-Programming-Language/dmd/pull/37).
* a few things haven't been backported to D1 yet
druntime:
* clean up Windows DLL support
phobos:
* nothing that I know of

Looks as though will be time to get std.parallelism in. But otherwise,
if you have anything you'd like to get into the next release, please
indicate so now.