COMP: OpenIGTLink - Fix MacOSX build error related to missing strnlen()

$ git shortlog ee594372eb8c9a25da1dbff2bd081cb70ce9554a..3ac531115f55e74265e7de7ff508312dbfb16695
Junichi Tokuda (4):
      BUG: Implement igtl::Strnlen() for platforms that do not have strnlen. See issue #25.
      STYLE: Increment the patch number.
      COMP: Fix compiler warnings for Mac OS X Mavericks.
      Merge pull request #27 from tokjun/25-missing-strnlen

Co-authored-by: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

From: Junichi Tokuda <tokuda@bwh.harvard.edu>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22681 3bd1e089-480b-0410-8dfb-8563597acbee