Added new param man.output.lang.in.name.enabled, which

Added new param man.output.lang.in.name.enabled, which
controls whether $LANG value is included in manpages
filenames and pathnames. It works like this:

If the value of man.output.lang.in.name.enabled is non-zero,
man-page files are output with the $lang value included in
their filenames or pathnames as follows;

- if man.output.subdirs.enabled is non-zero, each file is
  output to, e.g., a /$lang/man8/foo.8 pathname

- if man.output.subdirs.enabled is zero, each file is output
  with a foo.$lang.8 filename