add some discardable tags (sync with JOSM's list), closes #1423

Author: tyrasd

data/discarded.json

@@ -1,6 +1,5 @@
 {
   "created_by": true,
-  "converted_by": true,
 
   "odbl": true,
   "odbl:note": true,
@@ -53,5 +52,17 @@
   "yh:TOTYUMONO": true,
   "yh:TYPE": true,
   "yh:WIDTH": true,
-  "yh:WIDTH_RANK": true
+  "yh:WIDTH_RANK": true,
+
+  "LINZ2OSM:dataset": true,
+  "LINZ2OSM:layer": true,
+  "LINZ2OSM:source_version": true,
+  "LINZ:dataset": true,
+  "LINZ:layer": true,
+  "LINZ:source_version": true,
+  "linz2osm:objectid": true,
+
+  "fid": true,
+  "import_uuid": true,
+  "gnis:import_uuid": true
 }