When cloning a repository the following message is printed to stderr repeatedly:
"Operation name u'Checking out files' unknown - skipping line 'Checking out files: 1% (216/11210)'".

1. Does it makes sense to add the operation 'Checking out files' to the list of operations in the RemoteProgress._parse_progess_line()? (seehttps://github.com/gitpython-developers/GitPython/blob/master/git/util.py#L162)
2. Shouldn't the error logged by using the logging mechanism and not printed to stderr directly? (https://github.com/gitpython-developers/GitPython/blob/master/git/util.py#L242)

(Environment: Windows 7, Python 2.7.10, GitPython 1.0.1)