[phobos] No std.exception docs on D web site

[Jonathan M Davis]

On Saturday 14 August 2010 22:42:23 Lars Tandle Kyllingstad wrote:
> What the title says.  The std.concurrency docs refer to std.exception,
> but the latter isn't on the web site.
> 
> -Lars

As opposed to the incomplete std.gregorian which _is_ listed but isn't actually 
there (and given its incomplete state, it probably should be removed from the 
docs completely rather than adding its page).

- Jonathan M Davis