Translations, currency short notation, success message fixed

+ Added en_GB language file for template strings
+ Added currency short name to plugin config
+ The tooltip that shows the earned currency now shows the short notation instead of "gold"

I'm also looking for a way to [translate the tooltip](https://community.nodebb.org/topic/1907/how-to-get-formatted-translation-from-javascript). Any help appreciated.

The translations are loaded using your code from the openfantasy plugin.

If I made a mistake or there is a better way to do something please just say so, I'm always grateful for constructive feedback.