COMP: Modern gcc compilers have a reasonable template depth limit

Current gcc compilers have a reasonable max default template
depth. The -ftemplate-depth-50 flag was removed. This limited any
application which used ITK to only a template depth of 50.

Based on InsightSoftwareConsortium/ITK@5bcca741

From: Bradley Lowekamp <blowekamp@mail.nih.gov>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22807 3bd1e089-480b-0410-8dfb-8563597acbee