Some translation updates, and small backports.

1. Made user defined keyboard shortcuts more legible (#910 (closed), !4579 (merged)) (follow-up to another commit. Already documented in release notes)
2. Follow-up commit. No need to document. Backported from !4572 (merged)
3. Spanish translation provided by @lucasvieites in !4530 (closed)
4. Russian update, incorporates changes from 61ef7f6c. Decision to overwrite Alexandre's translations for now made in !4167 (closed)
5. "Add alignment option "pref" to translations". (no need to document)
   • Some strings were changed in 056a64a9, simply by the addition of |pref or a whitespace. I updated the translations so translator work does not get lost.
   • I also made some unnecessary changes in the same manner as above, however, the strings I touched had not been translated or were fuzzy (so my changes don't make a difference). It was simpler just to keep the changes than to undo them.
   • There were also a couple cases where the arguments were translated (but should not have been). I changed those.
   • is.po markup issues are a follow-up to !4562 (merged)