drop "Portable Toilets" preset

* rename generic amenity=toilets preset to "Toilets" (was: "Restroom"), as restroom is typically only used for indoor toilets, but the tag can also be used for outdoor ones
* rename field for "toilets" tag to "Restroom" (for the opposite reason as above)
* move alias "Water Closet" to "Flush Toilets" preset

fixes #1148

data/presets/amenity/toilets.json

@@ -30,17 +30,17 @@
         "privy",
         "head",
         "latrine",
+        "water closet",
         "WC",
         "W.C."
     ],
     "tags": {
         "amenity": "toilets"
     },
-    "name": "Restroom",
+    "name": "Toilets",
     "aliases": [
-        "Toilets",
+        "Restroom",
         "Bathroom",
-        "Lavatory",
-        "Water Closet"
+        "Lavatory"
     ]
 }

data/presets/amenity/toilets/disposal/flush.json

@@ -30,5 +30,8 @@
         "key": "toilets:disposal",
         "value": "flush"
     },
-    "name": "Flush Toilets"
+    "name": "Flush Toilets",
+    "aliases": [
+        "Water Closet"
+    ]
 }

data/presets/amenity/toilets/portable.json

@@ -1,29 +0,0 @@
-{
-    "icon": "temaki-latrine",
-    "fields": [
-        "toilets/disposal",
-        "{amenity/toilets}",
-        "toilets/handwashing"
-    ],
-    "moreFields": [
-        "{amenity/toilets}"
-    ],
-    "geometry": [
-        "point",
-        "area",
-        "vertex"
-    ],
-    "terms": [
-        "restroom",
-        "privy",
-        "porta john",
-        "porta potty",
-        "portapot",
-        "chemical toilet"
-    ],
-    "tags": {
-        "amenity": "toilets",
-        "portable": "yes"
-    },
-    "name": "Portable Toilet"
-}