ENH: Script to version the na-mic data tree on Midas

This script can be used to duplicate the Nightly NA-MIC data tree on
Midas to a new folder tagged by the release version. The script used the
pydas api as well as some of Midas web-api for the methods not yet
ported to pydas. The script does not take any input arguments. All the
arguments should be provided as options using the option flags. For a
full list of options: "python release.py --help".
For now, it is assumed this script does not depend on slicer python. It
can be used from the regular python interpreter.

Added a function called versionData that takes the same arguments as
input as the command line module. This facilitates the use of this
script as a python importable module.
Improved documentation. Added docstring style documentation for
functions.

Added a new directory called release that will contain all scripts
that can be used when tagging Slicer for a new release. For example,
versioning Midas NA-MIC data tree, documentation generation, etc.

Added dry run functionality that prints the structure of the source
folder that is going to be duplicated. Made changes to test script as
well.

Added a an "_" before all functions that are not required by the user to
hide them.
Added an __all__ in the __init__.py for the package to know which module
it can import.
So, when you do a
           from release import *
only, midasdata should be imported and not the unittest.

Fixes #2561
Fixes #2704

Co-authored-by: Jean-Christophe Fillion-Robin <JChris.FillionR@kitware.com>

From: Sankhesh Jhaveri <sankhesh.jhaveri@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22296 3bd1e089-480b-0410-8dfb-8563597acbee