DTRT wrt authorship info + using examples in "make check"

[Thien-Thi Nguyen]

i removed the face-lift comment and got carried away and started
removing authorship info.  now i'm having second thoughts, and in
consideration of how authorship is a highly motivational concept, will
reverse those particular edits.  my bad...

in other news, sounds like some recent changes broke some of the
examples.  probably it would be a good idea to add in each of the
example directories a line to the Makefile.am:

        TESTS = check.test

and then a simple script, e.g., examples/scripts/check.test:

        #!/bin/sh
    
        set -e
    
        guile -s hello > TMP
        echo "Hello, World!" | diff -u - TMP
        rm -f TMP

        [etc]

this way, top-level "make check" runs the examples, too.  this would be
exemplary methodology, as a bonus!  there's a small problem, though: the
examples rely on /usr/local/bin/guile being installed... hmmmm....

thi