* module/texinfo/string-utils.scm (end-of-sentence?): New procedure.
(make-text-wrapper): Append an extra space after LINE when it matches
`end-of-sentence?' and COLLAPSE-WHITESPACE? is false.
* test-suite/tests/texinfo.serialize.test ("test-serialize"): Adjust
accordingly.
* test-suite/tests/texinfo.string-utils.test ("text wrapping")["two
spaces after end of sentence"]: New test prefix.
* test-suite/tests/sxml.fold.test:
* test-suite/tests/sxml.ssax.test:
* test-suite/tests/sxml.transform.test:
* test-suite/tests/sxml.xpath.test:
* test-suite/tests/texinfo.docbook.test:
* test-suite/tests/texinfo.serialize.test:
* test-suite/tests/texinfo.string-utils.test:
* test-suite/tests/texinfo.test: Update licenses to GPL or LGPL 3+, and
update copyright holders to be FSF (where that is the case). Copyright
holders who are not FSF have their code in GPL/LGPL-compatible
licesnse.