GitLab

* based on rev 16a14ce of https://github.com/buildout/buildout/blob/1/bootstrap/bootstrap.py .
* update setuptools_source url to use the latest ez_setup.py so that the newest setuptools is used.

This reverts commit 4ac582c4.

This reverts commit f2be5210.

The idea *was* to not force providing external buildout. But then slapgrid
would have to get all not known dependencies, so it will be less usable.

Drop this way.

In slapos environment more flexibility on bootstrap process is required, and
slapos.buildout allows to select non-pypi location of zc.buildout distribution,
independently from setuptools/distribute location.

Thanks to partially reverting "Use only externally provided buildout."
(commit 2a0bbcc9) it is possible to use
slapgrid with provided buildout binary, but no one is forced to follow this
way, as old style internal bootstraping procedure is available.

Conflicts, manually merged:

	slapos/grid/slapgrid.py
	slapos/grid/utils.py