Add :qlot to *features* when qlot is loaded.
Some ASDF symbols seem to be not exported in some version.
Add 'with-local-quicklisp'.
Refactor.
Add docstrings.
Fix the path of quicklisp/setup.lisp.
Fix to ensure libraries installed correctly.
Improve with-local-quicklisp to work well if another system is already registered.
Fix the quicklisp-home during ensure-installed.