BUG: Recognize Clang compiler in FindCppcheck.cmake

Change-Id: Ic87a9bc3d10abc4050142c108ee031afc5e08004
BUG: Remove unused manual variables from superbuild of CTK

Change-Id: Ibe0891e6228021172f0da2efef3919b6e61a2665
Merge topic 'FindCppcheckClangCXX'

775ddb3 BUG: Recognize Clang compiler in FindCppcheck.cmake
Merge topic 'CMakeSuperbuildCTKWarnings'

789bd16 BUG: Remove unused manual variables from superbuild of CTK