cppcheck style warnings
Merge pull request #201 from aghayoor/cppcheck_style

cppcheck style warnings
cppcheck warnings that are marked as warning
Merge pull request #202 from aghayoor/cppcheck_warnings

cppcheck warnings that are marked as warning
ENH: Added test for gtractResampleDWIInPlace
ENH: Added conversion between Affine and (truncated) Rigid transform