i18n: Slay the dragon in favour of plain language

Replace terminology around dragons with plain language

Let's decide either way please.
<https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Mobile-frontend-settings-alpha/en>

jdlrobson: so MaxSem do we really need to kill the dragon?
[10:51am] jdlrobson: i'm going to miss the dragon 
[10:51am] MaxSem: too poetic
[10:51am] MaxSem: think of non-native speakers
[10:51am] jdlrobson: i know.. but think of the dragon
[10:52am] jdlrobson: that mythical beast weaving his way through the skies unleashing fire on the cold
[10:52am] jdlrobson: wreaking destruction and liberating the damsels imprisoned in the castles

Change-Id: If404eddee86c9cd8acf2b1275340962e46a96be3
Merge "i18n: Slay the dragon in favour of plain language"