Add area fill selector (wireframe/partial/full) to map data panel

also:
* style dark tooltips with shortcut keys
* use uppercase for shortcut keys

dist/locales/en.json

@@ -297,8 +297,9 @@
     "map_data": {
         "title": "Map Data",
         "description": "Map Data",
-        "show_features": "Show Features",
-        "show_layers": "Show Layers"
+        "show_features": "Show Map Features",
+        "show_layers": "Show Data Layers",
+        "fill_area": "Fill Areas"
     },
     "feature": {
         "points": {
@@ -350,6 +351,20 @@
             "tooltip": "Everything Else"
         }
     },
+    "area_fill": {
+        "wireframe": {
+            "description": "No Fill (Wireframe)",
+            "tooltip": "Enabling wireframe mode makes it easy to see the background imagery."
+        },
+        "partial": {
+            "description": "Partial Fill",
+            "tooltip": "Areas are drawn with fill only around their inner edges. (Recommended for beginner mappers)"
+        },
+        "full": {
+            "description": "Full Fill",
+            "tooltip": "Areas are drawn fully filled."
+        }
+    },
     "restore": {
         "heading": "You have unsaved changes",
         "description": "Do you wish to restore unsaved changes from a previous editing session?",