Use the Config mode of find_package to search for ITKConfig. This makes
FindITK a thin-wrapper around a standard find_package, bringing benefits
like searching lib64 paths when appropriate. This does for FindITK what
commit 2c1a01dc (Modernize FindVTK module, 2009-10-07) did for FindVTK.
This adds copyright/license notification blocks CMake's find-modules.
Many of the modules had no notices at all. Some had notices referring
to the BSD license already. This commit normalizes existing notices and
adds missing notices.
Brad King
Todd Gamblin
Ken Martin
Bill Hoffman