COMP: Updated ANTS to use tarball of BOOST as well.
COMP: Fix antsUtilities library linkage

When building BRAINSTools within DTIPrep antsUtilities
libraries were placed in the DTIPrep-build/lib directory
rather than the BRAINSTools-build/lib directory, so link
against the proper directory.
BUG: Regression from Dicom2Nrrd introduced

A DWI data set that was not represented in the DWI testing suite identified
a regression in the DWIConvert program introduced during refactoring.

This may be an issue with behavioral changes in DCMTK between stand-alone builds
and slicer builds, but that has not been confirmed.
ENH: Add feature to make SEMTools easier.
COMP: Min required Python is 2.6

Interpreter and libraries only need to be 2.6, BUT they must
match exactly.
ENH: Update all DTIPrep compatible SEM tools.
BUG: Warn if B Value or Gradients are missing, instead of throwing exception
Merge pull request #49 from Chaircrusher/DWIConvert_GEFix

BUG: Warn if B Value or Gradients are missing, instead of throwing excep...
WIP: convert double precision type transform to single type