lxqt_translate_desktop: Updates code to cope with the cmake-policy CMP0054
lxqt_translate_desktop: Updates code to cope with the cmake-policy CMP0054

This policy was introduced in CMake version 3.1. In any case the use of the
cmake_make_parse_arguments() function is the standard way of handle options.

Updates the documentation.

lxde/compton-conf,lxde/compton-conf