fixes #630 git statistics do too much work making them slow. added/changed/removed methods didn't use generator methods to return the list of changes - added test for that case
"""Various utilities to work with Python < 2.7.Those utilities may be deleted once ``vcs`` stops support for older Pythonversions."""importsysifsys.version_info>=(2,7):unittest=__import__('unittest')else:unittest=__import__('unittest2')