BUG: Fixed functions that call deprecated SimpleITK API changes

STYLE: print_workflow documentation and assertion

STYLE: renamed node so mapnode index doesn't append with session
ENH: Moved workflow printing to within subject loop to avoid multiple plotting

BUG: Atlas copying to cache now preserves timestamp of ExtendedAtlasDefinition.xml from FIRST run
Merge pull request #123 from BRAINSia/squashed_temp

BUG: Fixed functions that call deprecated SimpleITK API changes