setup: add a test for running setup.py `python3 -m pip install hg-evolve==9.2.0` currently fails, despite 9.2.0 being the first beta py3 release, because of unicode issues with the version number. `setup.py install` is a proxy test for pip install since it also suffers from similar, however the test currently fails due to running setup.py from a different directory to the one it is in. Also add a test for `hg version -v` with evolve enabled since a naive first solution for the pip issue was to just change `__version__` to a `u''` string, but that busts version display in `version -v`, which isn't currently picked up by tests.

# utility to setup pythonpath to point into the tested repository

export SRCDIR=`dirname $TESTDIR`
if [ -n "$PYTHONPATH" ]; then
    export HGTEST_ORIG_PYTHONPATH=$PYTHONPATH
    export PYTHONPATH=$SRCDIR:$PYTHONPATH
else
    export PYTHONPATH=$SRCDIR
fi