* CMake: Remove dead CODE_HEADER_FILES variable
* CMake: Remove dead COMMAND_CODE_HEADER_FILES and COMMAND_MOC_SOURCE_FILES
* CMake: Remove dead MOC_SOURCE_FILES and FORM_FILES_CPP references
* CMake: Remove dead HEADER_FILES reference
* CMake: Delete unused CustomPCH.cmake superseded by target_precompile_headers
* Implement a simple depth filter to cut all geometry below a certain level for intersections
* Add option to override all curve intersection cut depths from collection.
* Add support for showing intersection above or below threshold. Update label texts.