dimitri/el-get — pull request #901 by danielsz (2012-09-28 21:20:09+00:00)
Title: el-get-cleanup function

From the docs:

- **M-x el-get-cleanup**

Will remove all packages absent from the list of packages provided
as argument. This is most useful in the `user-init-file`
(`.emacs`), where you might want to remove all packages that have
been installed but not explicitly declared: `el-get-cleanup
my-packages`. This allows, in effect, to put under version control
only the `user-init-file` (`.emacs`), instead of the whole
`.emacs.d` directory, and still enjoy a truly portable emacs
configuration.