[toward-py3k] remove import with_statement (part of #2711624)
They are unneeded since we dropped python 2.5 compatibility. This will help
Python 3.3 experimentation.
# Run all scenarii found in windmill directoryfromos.pathimportjoin,dirnamefromcubicweb.devtools.cwwindmillimport(CubicWebWindmillUseCase,unittest_main)classCubicWebWindmillUseCase(CubicWebWindmillUseCase):#test_dir = join(dirname(__file__), "windmill/test_edit_relation.py")passif__name__=='__main__':unittest_main()