* 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* CMake: Delete unused CustomPCH.cmake superseded by target_precompile_headers
* Add surfio as submodule and create importer with tests
* Update compile fix when mio.h is included in multiple compile units
* Move file tools into RifFileTools