The comments in enumdata.py indicating macrolanguages meant nothing to
me, until I stumbled on a reference that lead me to ISO 639's usage of
the term. Add a minimal explanation to save such confusion for others.
Change-Id: Ia1d849d93a1d94c04c8c461debdecf879e9a7db5
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>