Add endonym for Maithili

Resolves https://github.com/mike-fabian/langtable/issues/2
“The Maithili language misses a "native" name” reported by Vratislav Podzimek

The endonym is from Wikipedia:

https://en.wikipedia.org/wiki/Maithili_language
https://de.wikipedia.org/wiki/Maithili

(CLDR does not yet have it).
Add test cases for endonym for Maithili

(It would be nice to have Maithili translations for “India”
and “Nepal” ...)
Return True by default from supports_ascii

If we don't have the information for the given layout, it is more likely
supporting ASCII characters than not.

Signed-off-by: Vratislav Podzimek <vpodzime@redhat.com>
Add grc (Ancient Greek)
Import some new translations for territories from CLDR
Import some new translations for languages from CLDR
Add eo (Esperanto)
Add ak (Akan) and GH (Ghana)
Add cop (Coptic)
Add dsb (Lower Sorbian)
Add fj (Fijian) and FJ (Fiji)
Add haw (Hawaiian)
Add hil (Hiligaynon)
Add la (Latin) and VA (Vatican City)
Add ln (Lingala), kg (Kongo language), CD (Democratic Republic of the Congo), CG (Republic of the Congo), and AO (Angola)
Add mos (Mossi language) and BF (Burkina Faso)
Add ny (Nyanja language) and MW (Malawi)
Add qu (Quechua) and quh (South Bolivian Quechua)
Add smj (Lule Sami)
Add tet (Tetum language) and TL (East Timor)