do not care for backend user stuff in core

--HG--
branch : 0.9
addon loading is part of the app

--HG--
branch : 0.9
remove non-addOn dependencies from the requirement list

We cannot be sure that we know all vendor libraries. For example, one addOn can
require "guzzle/http", whereas another one requires "guzzle/guzzle" (the
complete package). Composer will now install only the full package and hence
our addOn service would constantly think that "guzzle/http" is missing.
Without *deep* understanding of the package graph at runtime, we cannot resolve
this, so we start relying even more on Composer to put together a working
combination of packages.

If you clone your addOn manually, be sure you know what you're doing.

--HG--
branch : 0.9
extra : rebase_source : 2737e5be539f6ed6be2e7bf3d44b09d4d96e029b
return a much more useful value from db->query()

--HG--
branch : 0.9