* externals-list: Remove subtree async.
* packages/async/async-pkg.el: Remove, it is a generated file.
(("ack" :subtree "https://github.com/leoliu/ack-el")
("aggressive-indent" :subtree "https://github.com/Malabarba/aggressive-indent-mode")
- ("async" :subtree "https://github.com/jwiegley/emacs-async")
("auctex" :external "git://git.sv.gnu.org/auctex.git")
("bug-hunter" :subtree "https://github.com/Malabarba/elisp-bug-hunter")
;;FIXME:("cedet" :external "??")