Add full linking-set to clisp 2.49
Update SBCL to 1.1.12
Adding ASDF package definition system for Common Lisp
Adding a Common Lisp wrapper.

Features:
  + configurable via environment variables
  + can skip the actual launching of the lisp implementation (source it
  with NIX_LISP_SKIP_CODE=1 to get all the settings)
  + currently supports SBCL, CLisp, ECL
  + determines lisp implementation from NIX_LISP_COMMAND variable or
  from buildInputs
  + sets ASDF search path for packages using buildInputs
Adding lisp-packages subset. Adding a few test packages without dependencies.
Adding fresh StumpWM built via lisp-packages
Replacing StumpWM with a fresh lisp-packages version