add unit and language handling for weather provider darksky
add unit and language handling for weather provider darksky

MichMich/MagicMirror,roramirez/MagicMirror,Tyvonne/MagicMirror,MichMich/MagicMirror,MichMich/MagicMirror,Tyvonne/MagicMirror,heyheyhexi/MagicMirror,Tyvonne/MagicMirror,Tyvonne/MagicMirror,roramirez/MagicMirror,MichMich/MagicMirror,heyheyhexi/MagicMirror,roramirez/MagicMirror,roramirez/MagicMirror,n8many/MagicMirror,heyheyhexi/MagicMirror,n8many/MagicMirror,heyheyhexi/MagicMirror,n8many/MagicMirror,n8many/MagicMirror,n8many/MagicMirror