libtool: rearrange header comments for correct version/help extraction.

* m4/libtool.m4 (_LT_COPYING): Rearrange the comments output to
the generated libtool script so that --version and --help behave
the same as pre-funclib.sh revisions.
(_LT_CONFIG_SAVE_COMMANDS): Likewise.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>