Using Shell while importing "foo" creates a subroutine "foo" in the name space
of the importing package. Calling "foo" with arguments "arg1", "arg2", ...
results in a shell command "foo arg1 arg2...", where the function name and the
arguments are joined with a blank.
This package is included as a show case, illustrating a few Perl features. It
shouldn't be used for production programs.
