Remove all composer related code

Revert "Fix Composer insanity…" (53c121c37ded6841d2aa67281c55b104faa6d77b)
Revert "import() wildcard * supports Composer." (85f1b0f7d1b879032409bffbc3375e422f058086)
Revert "Extend Composer support to hoa:// protocol." (943f893f1ffe06afd576909fb62c2aa4f354f47a)