added --version.
Add App::shelly::command and refactored by using it.
Stop redirecting the standard error to the standard output.
Updated bin/shly.
Also search shlyfile.{lisp,cl}.
Ensure shelly_path ends with a slash.
Also load ~/.shelly/shlyfile.
Don't use dumped-core when SHELLY_PATH is specified.
Replace sb-ext:quit by sb-ext:exit. sb-ext:quit is deprecated now.
Put the core option first.