ELS 2015 was awesome! Just so you know.
A fully featured build system for CL would actually include provisions for configuring a library.
Lisp, where people might very well ask you "Which flavour of 'if' would you like?"
Joda-Time (or it's successor) should be ported to CL, it's badly needed.
(global-set-key (kbd "H-1") ...) Hyper Hyper! In other words, bind
Hyper and rejoice!