Base class for FuzzyOverlap misc tool

Some details are still to be fixed
Working version
Added inputs&outputs descriptions

PR #622
Run autopep8 on misc.py

In-place run of the standard tool. Ref #662
PEP8 for the whole interface

Fixed all errors. #622
Added dummy files so doctest doesn't fail

Files added in response of https://github.com/nipy/nipype/pull/622#discussion_r5921360
Fixed filenames in documentation

Minor change, as the names were not descriptive.
Merge pull request #622 from oesteban/enh/FuzzyOverlap

Fuzzy overlap Jaccard and Dice indices computation
Merge branch 'master' of https://github.com/nipy/nipype into base
Add join feature.
Refactor join into JoinNode rather than a Join interface.
Clean up white space.
Remove obsolete joinsource Node init parameter.
Validate the join fields.
Set a non-list join field item type to Any.
Clean up white space.
Iterate with nodes_iter rather than nodes.
Support a Set join field.
Support an identity join node.
The joinfield default is all input fields.
Insert a J in the join item field name.
Improve comments.
Support multiple join fields.
Support the unique flag.
Remove extraneous debug message.