Store changesets_count in a changeset tag

(it will say "0" for someone making their first edit)

modules/ui/commit.js

@@ -11,11 +11,18 @@ import { utilRebind } from '../util';
 
 
 var changeset;
-var readOnlyTags = ['created_by', 'imagery_used', 'host', 'locale'];
+var readOnlyTags = [
+    'changesets_count',
+    'created_by',
+    'imagery_used',
+    'host',
+    'locale'
+];
 
 
 export function uiCommit(context) {
     var dispatch = d3.dispatch('cancel', 'save'),
+        userDetails,
         _selection;
 
     var changesetEditor = uiChangesetEditor(context)
@@ -122,6 +129,8 @@ export function uiCommit(context) {
 
             var userLink = d3.select(document.createElement('div'));
 
+            userDetails = user;
+
             if (user.image_url) {
                 userLink
                     .append('img')
@@ -323,6 +332,13 @@ export function uiCommit(context) {
             }
         }
 
+        // always update userdetails, just in case user reauthenticates as someone else
+        if (userDetails && userDetails.changesets_count !== undefined) {
+            tags.changesets_count = String(userDetails.changesets_count);
+        } else {
+            delete tags.changesets_count;
+        }
+
         if (!_.isEqual(changeset.tags, tags)) {
             changeset = changeset.update({ tags: tags });
         }