Fix unprivileged build. Remove libtool from USE_AUTOTOOLS.
Make sure that Makefile.am is patched, a Makefile.in patch is useless
with USE_AUTOTOOLS=automake.
Remove libtool from USE_AUTOTOOLS, USES already contains libtool, to
fix a DEVELOPER=yes warning.
Approved by: portmgr (blanket "just fix it" approval)