Calculate file history always from latest changeset to always show full history. When doing the calculation from a particular changeset git doesn't any records from parent changesets
"""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')