[Mediawiki-i18n] Lowercase first letter in MediaWiki language names

[Robin Pepermans]

Hi,

As mentioned in my previous e-mail, I was going to make the first
letter of language names lowercase where this is usual (like Français
-> français) to make it consistent with CLDR. This was also to make it
possible to prefer MediaWiki names over CLDR names, so autonyms always
use the MediaWiki name (it also makes the output of {{#language:xyz}}
and {{#language:xyz|xyz}} consistent).
While it is ultimately best to provide corrections to CLDR as well,
this takes a lot of time and it is better if they're already in
MediaWiki. For example, with this change, 'mapudungun' will always be
shown, instead of 'araucano'.

Please review the changes in
https://gerrit.wikimedia.org/r/#/c/7306/1/languages/Names.php  If the
name of your language is also written with lowercase first letter,
I'll change it in a later update.

Thanks,
Robin