bbatsov/prelude — pull request #432 by 7696122 (2013-11-09 08:00:52+00:00)
Title: customise package-user-directory

https://github.com/bbatsov/prelude/pull/232

above pull makes that user can't customise package-user-directory.

so, before loading prelude-pacakge, load custom-file and

if `prelude-use-package-user-directory' is non-nil, set package-user-dir to be relative to Prelude install path.