try to avoid requiring setuptools to install EasyBuild

[boegel]

cfr. #2428

[boegel]

fixed for:

• easybuild-framework (see stop trying to use setuptools.setup in setup.py, always use distutils.core.setup instead #2988)
• easybuild-easyblocks (see stop trying to use setuptools.setup in setup.py, always use distutils.core.setup instead easybuild-easyblocks#1793)
• easybuild-easyconfigs (stop trying to use setuptools.setup in setup.py, always use distutils.core.setup instead easybuild-easyconfigs#8866)
• easybuild (stop trying to use setuptools.setup in setup.py, always use distutils.core.setup instead easybuild#542)

[boegel]

All done, so closing this...