niftyfit-interface: Added an interface for the DWI fitting options in NiftyFit.
niftyfit-interfaces: Added some minor additional functionality to niftyfit and reg_average
niftyreg-interface: bug-fix: the lncc_val can take negative values
Merge branch 'niftk-interfaces-enhancements' of https://github.com/ntoussaint/nipype into niftk-interfaces-enhancements