Makefile.am: Update commentary

* Makefile.am, am/Makefile.am, doc/Makefile.am, tests/Makefile.am: Update
  commentary.
tests/Makefile.am (CLEANFILES): Remove
doc/guile-dsv.texi (Introduction): Update description

* doc/guile-dsv.texi (Introduction): Update description.
* doc/version.texi: Update.