"*.mo" files are not installed in the case of clean installation
Created originally on Bitbucket by Katsunori FUJIWARA
Current "setup_posix()" generates list of "*.mo" files to be installed from existing files under "locale" directory.
But in the case of clean installation, such ".mo" files don't exist yet at generation above, so ".mo" files are not installed, even though they are generated by "setup.py install".