Add settings page for Storage, add notification prefs

app/views/settings/_remotestorage.html.erb

@@ -0,0 +1,25 @@
+<%= form_for @user, url: setting_path(:remotestorage), html: { :method => :put } do |f| %>
+<section>
+  <h3>Notifications</h3>
+  <ul role="list">
+    <%= render FormElements::FieldsetComponent.new(
+      positioning: :horizontal,
+      title: "New connection authorized",
+      description: "Notify me when my storage is connected to a new app"
+    ) do %>
+      <% f.fields_for :preferences do |p| %>
+        <%= p.select :remotestorage_notify_auth_created, options_for_select([
+          ["off", "disabled"],
+          ["Chat (Jabber)", "xmpp"], # TODO make DRY, check for XMPP enabled
+          ["E-Mail", "email"]
+        ], selected: @user.preferences[:remotestorage_notify_auth_created]) %>
+      <% end %>
+    <% end %>
+  </ul>
+</section>
+<section>
+  <p class="pt-6 border-t border-gray-200 text-right">
+    <%= f.submit 'Save', class: "btn-md btn-blue w-full md:w-auto" %>
+  </p>
+</section>
+<% end %>