i18n: consistency tweaks

* remove full-stops
* add GENDER support and use an output mode per
  https://www.mediawiki.org/wiki/Manual:Messages_API

Spotted by Siebrand
* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Mobile-frontend-history-no-results/en
* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Mobile-frontend-profile-usertalk/en
Spotted by Ebraminio
* https://translatewiki.net/wiki/Thread:Support/MediaWiki:Mobile-frontend-last-modified-with-user-minutes/en

Change-Id: I27767f015c83996765ca5381cee56e76e7e73fcc
Merge "i18n: consistency tweaks"