Spanish (Spain) translation update (#2882)

* Spanish (Spain) translation update

 - Updated the .ts file itself (seems that es-es was forgotten at the last code update pass).
 - Translated new strings.
 - Fine-tuned others.
 - Cleaned up now-unneeded strings.

* Spanish (Spain) translation update

 - Updated the .ts file itself (seems that es-es was forgotten at the last code update pass).
 - Translated new strings.
 - Fine-tuned others.
 - Cleaned up now-unneeded strings.