makes the language configurable for each site, it reads the "Lang" parameter...

makes the language configurable for each site, it reads the "Lang" parameter from awstats.DOMAIN.conf before it gets deleted and adds the parameter to the content before the new config file is written.
the "-lang" parameter is removed from the awstats-command, so the global value for lang in awstats.conf.local or the value in awstats.DOMAIN.conf gets respected. Closes #3668