Add DTIAtlasFiberAnalyzer extension

see issue # 164
Merge pull request #166 from booboo69500/164-add-DTIAtlasFiberAnalyzer

Add DTIAtlasFiberAnalyzer extension - This extension provides a tool to analyze fiber tracts from Diffusion Tensor Images (DTI). One gives the tracts an average space and provides the transforms to move the tracts from the average space to each individual image. The software will compute various metrics along the fibers in the subjects space.