check for libtool in autogen.sh

[Sven Neumann <sven gimp org>]

Hi,

we've just discovered that 'libtool --version' doesn't work on MacOS X
and this breaks autogen.sh from gtk+ and friends:

  if libtool --version < /dev/null > /dev/null 2>&1 ; then

Actually the libtool version is checked using 'libtoolize --version',
so that line should probably read 

  if libtoolize --version < /dev/null > /dev/null 2>&1 ; then

Taking a closer look at the line that follow I found another oddity:

  libtool_version=`libtoolize --version |  libtoolize --version | sed
                                        ^^^^^^^^^^^^^^^^^^^^^^^
Is this intentional?


Salut, Sven