COMP: Remove unneeded FindCTK.cmake

When initially added in r15226, the FindCTK.cmake module allowed to
overcome an issue with "find_package" command preventing it from understanding the
REQUIRED parameter when dealing with Config file.

CMake 2.8.8 doesn't have this limitation anymore, CMake commit fa0f0654
fixes the issue.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21868 3bd1e089-480b-0410-8dfb-8563597acbee