update third-party to libffi-3.0.13

3.0.13 includes support for aarch64
also bump rpm release number
also update libxml2-2.9.1 for aarch64
build libxml2 without python support
patch to fix /usr/lib64 to /usr/lib for libffi
Merge remote-tracking branch 'remotes/jbastian/libffi-update' into libffi-update
revert spec file changes so tito doesn't get confused.
Automatic commit of package [restraint] release [0.1.6-1].