"Show reblogs" per-follower UI/database changes

TODO:

* Tests (particularly for FollowRequests).
* Anything to respect the setting when putting reblogs in timelines.

app/javascript/mastodon/features/account_timeline/containers/header_container.js

@@ -68,6 +68,14 @@ const mapDispatchToProps = (dispatch, { intl }) => ({
     dispatch(mentionCompose(account, router));
   },
 
+  onReblogToggle (account) {
+    if (account.getIn(['relationship', 'following', 'reblogs'])) {
+      dispatch(followAccount(account.get('id'), false));
+    } else {
+      dispatch(followAccount(account.get('id'), true));
+    }
+  },
+
   onReport (account) {
     dispatch(initReport(account));
   },