Added language and theme settings.

lang/da-DK.json

@@ -28,6 +28,7 @@
   "label.enable-share-url": "Aktivér delings-URL",
   "label.invalid": "Ugyldig",
   "label.invalid-domain": "Ugyldigt domæne",
+  "label.language": "Language",
   "label.last-days": "Sidste {x} dage",
   "label.last-hours": "Sidste {x} timer",
   "label.logged-in-as": "Loggede ind som {username}",
@@ -50,6 +51,7 @@
   "label.settings": "Indstillinger",
   "label.share-url": "Del URL",
   "label.single-day": "Enkelt dag",
+  "label.theme": "Theme",
   "label.this-month": "Denne måned",
   "label.this-week": "Denne uge",
   "label.this-year": "Dette år",