Use "Fully blank" instead of "white votes"

We were mistranslating the Spanish word "blanco", which can mean "blank"
or "white".

We've also decided to use "fully blank" because polls may have many
questions, and only votes leaving everything blank count as blank votes.

config/locales/en/general.yml

@@ -661,7 +661,7 @@ en:
         booth: "BOOTH"
         total: "TOTAL"
         valid: "Valid"
-        white: "White votes"
+        white: "Fully blank"
         null_votes: "Invalid"
       results:
         title: "Questions"

config/locales/es/general.yml

@@ -661,7 +661,7 @@ es:
         mail: "CORREO"
         total: "TOTAL"
         valid: "Válidos"
-        white: "En blanco"
+        white: "Totalmente en blanco"
         null_votes: "Nulos"
       results:
         title: "Preguntas"