[phobos] emplace with classes, also fixes issue 5522 (#246)

[Andrei Alexandrescu]

For the rest of this release cycle I'll let Walter pull in requests as 
he finds fit.

Thank you Walter for stoically enduring my stream of late pull merges 
over the past few days. I'll stop here.


Andrei

On 9/6/11 11:46 AM, blackwhale wrote:
> This is pull request for patch by KenyTM found in bugzilla:
> http://d.puremagic.com/issues/show_bug.cgi?id=5522
>
> FWIW it should fix a lot of other calaterial damage caused by emplace with classes being unusable.
> This also supersedes pull 245, except possible gain in preformance.
>