PERF: BCD Use all the number of threads by default

BCD was being forced to run in single threaded mode.
This was greatly increasing the amount of time it took
to run the BCD tests.
ENH: Update to ITK for new features needed by BRIANSTools.
COMP: Removed compiler warning about unused variables.
BUG: Tests require paths relative to build tree.

The BABCsmall test was referencing a hard-coded NFS path
that does not exists outside of the primary development
environment.
COMP: Bump ITK version tag