Make dub part of the standard dmd distribution

[Nick Sabalausky via Digitalmars-d]

On 06/04/2015 04:39 AM, Sönke Ludwig wrote:
>
> Of course you could make the system completely build
> tool agnostic, but then you'd basically lose interoperability between
> packages, as each package might choose its own build tool.
>

With this PR and the upcoming follow-up to add 
--format=(list|some_compiler|whatever), there is NO issue with package 
interoperability (as long as a package's "import-paths" is correct):

https://github.com/D-Programming-Language/dub/pull/572

Note that even WITHOUT dub, packages from different buildsystems 
*already* interop just fine. Even in C-land. All you ever need for 
packages to work together is the appropriate "build this package" 
command and the import/lib paths for the compiler/linker. Buildsystem is 
a package-local issue, not a cross-package issue.