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 #122 from BRAINSia/davemaster

ENH: Workflow updates for Track experiment