fix east slavic pluralization for float numbers
Change confirmation error message  for es-* locales

This follows the changes introduced in rails/rails#5942, but does not include the attribute name in the message because it reads weird and it would require adding an article, which in turn would require knowing the grammatical gender of the attribute. E.g., "no coincide con *la* contraseña" or "no coincide con *el* número de cuenta".
Change Swedish taken error message.
Merge pull request #490 from calleerlandsson/master

Change Swedish taken error message.
Merge pull request #486 from simpl1g/master

fix east slavic pluralization for float numbers
Merge pull request #487 from tjku/master

Sort keys in Polish translation and add the missing ones
Merge pull request #488 from epidemian/confirmation-error-es

Change confirmation error message  for es-* locales