Examine the selected libtoolize in order to determine it's configured

  Examine the selected libtoolize in order to determine it's configured
  libtool.m4 path, rather than gross assumptions.  Leaving the gross
  assumptions as a fail-over if the structure of libtoolize script is
  somehow borked.

  Prefer, of course, any libtool that isn't libtool 1.3 or before, so
  push 'libtoolize' to the end of the desireables list.

  In the sandbox for some testing across platforms - will propose to
  dev@apr once some measure of portability is confirmed

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/fips-dev@190009 13f79535-47bb-0310-9956-ffa450edef68