obsolete D libraries/modules

[Andrej Mitrovic]

On 9/3/13, Andrei Alexandrescu <SeeWebsiteForEmail at erdani.org> wrote:
> Yep, that's the one. http://d.puremagic.com/issues/show_bug.cgi?id=3780.

Another impotant note to make is that the pull for #3780 was made
before UDAs were available.

Now that we have them, we can make a more reliable and readable API
rather than have to depend on argument position rules. For example:

getopt(args,
    "count", &count, @doc("This is the thread count"));