Update documentation and version output

Update documentation and version output

* libtoolize.in: Overwrite function in bootstrap for printing version
  information for libtoolize.
* build-aux/ltmain.in: Overwrite function in bootstrap for printing
  version information for libtool.
* doc/libtool.texi: Fix typo and correct references for tests/demo
  subdirectory to the tests/demo.at Autotest file.
* gl/top/README-release.diff: Add documentation for maintainers so
  the CVS repository is properly updated following a stable release.