[R6RS] Naked scripts

[dyb at cs.indiana.edu]

Thee's no need for (script library-name); the idea with the script form
was to let the script evaluator know the name of the library and entry.
I don't like the /usr/bin/env solution either, but I do like requring
the imports to be specified.  The #!r6rs can be optional as far as I'm
concerned.

So I propose this instead:

  #!/usr/bin/scheme-script <line break> <optional #!r6rs>
  (import <import-spec>*)
  <library body>

with a nullary procedure command-line that returns the command-line, with
the name of the script first followed by the arguments as strings.

We can consider whether to use your <relaxed library body> instead, but
I'm inclined not to do so.

Mike can get the debugability he wants with conventions for structuring
scripts, and users wanting to avoid the COBOL look-and-feel can go with
something simpler.

Kent