BUG: cmake/SuperBuild: Ensure svn and git paths are propagated
BUG: cmake/SuperBuild: Ensure svn and git paths are propagated

This commit fixes issue #126 by completing the patch initially integrated in
b3ea5fa (BUG: cmake/SuperBuild: Only propagate svn and git paths if valid values)

QIICR/dcmqi,QIICR/dcmqi,QIICR/dcmqi,QIICR/dcmqi,QIICR/dcmqi