post tooltips: add disable option (#3689).

* Add "disable post tooltips" account setting.
* Add back title attribute for when fancy tooltips are disabled.

app/views/layouts/default.html.erb

@@ -25,6 +25,7 @@
   <meta name="style-usernames" content="<%= CurrentUser.user.style_usernames? %>">
   <meta name="last-forum-read-at" content="<%= CurrentUser.user.last_forum_read_at %>">
   <meta name="disable-labeled-saved-searches" content="<%= CurrentUser.disable_categorized_saved_searches? %>">
+  <meta name="disable-post-tooltips" content="<%= CurrentUser.disable_post_tooltips? %>">
   <%= content_tag(:meta, nil, name: "disable-mobile-gestures", content: CurrentUser.disable_mobile_gestures?) %>
   <%= auto_discovery_link_tag :atom, posts_path(:format => "atom", :tags => params[:tags]) %>
   <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.css" integrity="sha256-rByPlHULObEjJ6XQxW/flG2r+22R5dKiAoef+aXWfik=" crossorigin="anonymous" />

app/views/users/edit.html.erb

@@ -78,6 +78,8 @@
 
         <%= f.input :disable_mobile_gestures, :as => :select, :collection => [["No", "false"], ["Yes", "true"]], :include_blank => false %>
 
+        <%= f.input :disable_post_tooltips, :as => :select, :hint => "Disable advanced tooltips when hovering over thumbnails", :collection => [["No", "false"], ["Yes", "true"]], :include_blank => false %>
+
         <%#= f.input :disable_cropped_thumbnails, :as => :select, :collection => [["No", "false"], ["Yes", "true"]], :include_blank => false %>
 
         <div class="input text optional field_with_hint">