Run: git submodule add git://git.savannah.gnu.org/libtool.git dependencies/libtool
Remove the built-in libtool, to switch to Git
Check out libtool v2.4.2
Attempt to completely move the the included libtool
Remove autoconf, switching to a Git submodule
Run: git submodule add git://git.sv.gnu.org/autoconf dependencies/autoconf-2.69
Merge Git submodule work

Merge remote-tracking branch 'origin/master'