Detecting if the installer is being run to install buildout itself.

A working_set passed into install() is the sign that we're called from
buildout.py to install buildout, setuptools, an extension or a recipe.
Those need the global pkg_resources.working_set, for instance to load entry
points.

So... conflicts with global packages are possible, but they should be ignored
so that we can grab the right versions ourselves. The paths that end up in the
bin scripts that we generate are OK.
Requiring setuptools > 3.3 for the replace=True option on working_set.add()

Perhaps older versions also support this option, but at least 0.7.2 does not.
So I picked the oldest version I had handy in my buildout egg cache...
Updated changelog
Fix and reenable Python 2.6 tests on Travis

Closes #202.
Better handling of unknown PYTHON_VER in Makefile

If PYTHON_VER is not known to the Makefile, don't fall back to
PYTHON_MINOR of 2.7.3, instead ask the user to specify a correct
PYTHON_MINOR explicitly.  Otherwise you get weird failures like #203.

Also allow the user to override PYTHON_MINOR on the `make` command line,
e.g.

    make PYTHON_VER=3.3 PYTHON_MINOR=3.3.6
Print dots while running tests

Travis thinks something is wrong when the script produces no output in
10 minutes, which leads to sporadic test failures like
https://travis-ci.org/buildout/buildout/jobs/39916822
Fix and reenable Python 3.4 tests on Travis

Closes #203

Some background: PEP 453 introduced the 'ensurepip' module to Python 3.4.
'make install' runs 'python3.4 -m ensurepip' which installs setuptools
into site-packages.  Our test suite doesn't like that.  Luckily,
Python's ./configure has an option to disable ensurepip.
Handle changed NameError wording in Python 3.4

Should fix https://travis-ci.org/buildout/buildout/jobs/39918144
Merge pull request #201 from reinout/reinout-fix-193-again

Fix for the #198 fix
Release 2.2.5

Contains fix for #198
Claim Python 3.4 support

Tests with Python 3.4 passed on Travis, for a bit.
Add a tox.ini

This simplifies testing all Python versions to 'tox'.

Unfortunately detox cannot be used to run the tests in parallel since
dev.py scribbles directly into the top-level of the source tree (in
bin/).
Fix test failures introduced in 067acf75397

PKG-INFO for setuptools 3.3 has non-ASCII characters.  This causes
two test failures on Python 2, one of them rather unobvious
(testing_bugfix.txt complains about the different number of logging
handlers, of all things).