* gnu/packages/patches/openbox-python3.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/openbox.scm (openbox)[source]: Apply it.
[arguments]: New field.
[propagated-inputs]: Replace python2-pyxdg with python-pyxdg.
[native-inputs]: Replace python-2 with python-wrapper.
Add autoconf, automake, gettext-minimal and libtool.