if a port needs 2.x then set MODPY_VERSION=${MODPY_DEFAULT_VERSION_2}.
This commit doesn't change any versions currently used; it may be that
some ports have MODPY_DEFAULT_VERSION_2 but don't require it, those
should be cleaned up in the course of updating ports where possible.
Python module ports providing py3-* packages should still use
FLAVOR=python3 so that we don't have a mixture of dependencies some
using ${MODPY_FLAVOR} and others not.
Supuner (SUPpress UNless ERror) executes a command and manipulates its
stderr and stdout, allowing the user control over when they are
displayed and / or outputted.
From Laurence Tratt with minor tweaks from myself and kili.
OK kili@
