add ExtractMainComponent interface
Merge branch 'master' into enh/freesurfer

* master: (255 commits)
  fix: version property
  doc: added pointer to ants example
  fix: removed cma to freesurfer mapping, updated docs and pointed to atlas/template downloads
  fix: remove np deprecation decorator and moved imports to run_interface.
  fix: explicitly test for nipy version and remove imports to specific interfaces closes #648
  Added FuzzyOverlap to changelog
  fix: set slice_times as seconds outside workflow generating function
  fix: replaced plugin_args with proper arguments
  enh: replace realignment routine with newer Nipype interface for Nipy's newer class
  enh: added SpaceTimeRealign from nipy 0.4.dev
  api: always run datasink and let copyfiles decide if things need to be copied or not. in case inputs are directories, this will allow refreshing outputs.
  fix: moved imports for dicominfo outside of the function
  fix: use ceiling of slice thickness for erosion purposes
  fix: add imports to the functions
  enh: compressing more into functions
  enh: replaced erosion with slicethickness and added epimask support for bbregister
  fix: updated ants example to use new parameters from ants
  tst: fixed ants doctests to indicate smoothing sigmas
  enh: updated antsApplyTransforms to accept input image type
  api: changed smoothing sigmas to accept float in antsRegistration
  ...
Merge branch 'master' into enh/freesurfer

* master:
  fix: afni url in afni package
  added more documentation
  Added dummy files
  fixed inputs for Retroicor
  adding retrocicor to __init__.py
  addition of 3dretroicor interface, very basic version
  enh: allow naming a workflow
  microseconds
  microseconds
  fix:total_seconds_python2.6
  fix: missing template
  enh: updated mindboggle atlases
  DOC: Add short doc page for SelectFiles
allow freesurfer resume... test
allow freesurfer resume, wip
fix logging
fix logging
fix logging
fix freesurfer steps  resume
Merge branch 'master' into enh/freesurfer

* master:
  add DicomImport to spm init.py
  fix merge conflict in CHANGES
  add interface for spm's dicom import
  spm wants a two-item array here
  Fence matplotlib import with try block
  Get backend configurable from node config
  Set matplotlib backend from config in pyscript
  Attempt to set backend in local matplotlib
  fix: matplotlib import to inside function
  added changelog information
  enh: update internal prov to latest version of external library
  added hash_file protocol and dummy test file
  Remove inheritance_diagram.py.
  now able to set prefix and file extension automatically NIFTI
  include AFNItoNIFTI in module init file
  include 3dAFNItoNIFTI command in interfaces.afni
enh: added options to execute script from command line
Merge pull request #682 from satra/enh/openfmri

few cosmetic improvements to openfmri script
fix: mesh import to enable doc building
Merge pull request #684 from satra/fix/docbuilding

fix: mesh import to enable doc building
ref: changing filename generation to a more consistent model
fix: added name_template to metadata keys
fix: make sure mandatory=False items are displayed
fix: make sure mandatory=False items are displayed
fix: removed all mandatory=False
Merge pull request #685 from satra/fix/mandatory

fix: make sure mandatory=False items are displayed