Treat :user in profile.clj as project map when outside of project. Fixes #931.

By treating the `:user` profile in `profile.clj` as the project map when one's
outside of a project, the default repositories among with any mentioned
repositories within the `:user` profile will be fetched without any issues. Also
works fine when `profile.clj` doesn't contain any `:user` profile or no
`profile.clj` exists.