Add more translation variables for statistics pages in frontend

Also translated some text parts to Tagalog.

frontend/tl/catalogue.json

@@ -1,10 +1,10 @@
 {
     "catalogue": {
-        "volume": "Volume",
-        "public": "Public",
-        "not_public": "Not public",
+        "volume": "Tomo",
+        "public": "Hayag",
+        "not_public": "Tago",
         "title_main": "Museum-Digital",
-        "title_sub": "Catalogue of objects for",
-        "generated": "Generated"
+        "title_sub": "Katalogo ng mga bagay ukol sa",
+        "generated": "Lumikha"
     }
 }

frontend/tl/statistics.json

@@ -16,6 +16,29 @@
         "most_popular_objects": "Most Popular Objects",
         "popular_all_time": "Most Popular of All Time",
         "popular_this_month": "Most Popular Objects of This Month",
-        "popular_today": "Most Popular Objects of Today"
+        "popular_today": "Most Popular Objects of Today",
+        "images": "Images",
+        "resources": "Resources",
+        "resouces": "Resources",
+        "transcriptions": "Transcriptions",
+        "museum_records": "museum records",
+        "collection_records": "collection records",
+        "object_records": "object records",
+        "literature": "literature entries",
+        "appointments": "Appointments",
+        "articles": "Articles",
+        "series": "object groups",
+        "events": "events",
+        "links": "links",
+        "distinct_persinst": "distinct actors",
+        "distinct_places": "distinct places",
+        "distinct_times": "distinct time entries",
+        "distinct_tags": "distinct tags",
+        "avg_text_len": "average text length",
+        "avg_puqi": "average quality score",
+        "note": "Note",
+        "note_old_statistics": "All statistical data before December have been retrospectively generated based on existing data and should be taken as educated guesses.",
+        "download_statistics": "You can download the full statistics by clicking <a href=\"index.php?t=statistics&output=csv\">here<\/a>.",
+        "since": "since"
     }
 }