Implement a full command set for ql-to-deb binary.

The usage output is now more interesting:

./build/bin/ql-to-deb [ option ... ] command [ package ...]

Options:
  --help -h                       boolean  Show usage and exit.
  --version -V                    boolean  Displays version and exit.
  --verbose -v                    boolean  Be verbose.
  --fix-bugs -F                   boolean  Fix packaging bugs.
  --config -c                     string   configuration file.  (default: #P"/vagrant/ql-to-deb.ini")
  --dir -D                        string   where to build packages.  (default: "/tmp/ql-to-deb/")
  --logs -L                       string   where to write detailed logs.  (default: "/tmp/ql-to-deb/logs/")
  --quicklisp -Q                  string   URL to use to fetch quicklisp.txt main file  (default: "http://beta.quicklisp.org/dist/quicklisp.txt")

Commands:
  status    Compare versions (debian sid, local, Quicklisp)
  check     List packages that need building
  update    Build either packages or all that need a build
  lint      Run lintian on just built packages
  sign      Run debsin on just built packages
  upload    Run dput on just built packages
Update debian packaging of ql-to-deb.