This is what I do: copy them from an autotools install into the cmake project.
Package.cpp and config.h.cmake has to be fixed.
* check that .tar.gz and .xz are identical to those from autotools
- * DONE: Fix libintl, LYX_EXTERNAL_LIBINTL=OFF triggers compilation in intl even when LYX_NLS is OFF
* *.po are too often generated by Visual Studio
* show correct values in cmake-gui: write forced to cache