Add ability to use nested only parameter

- The only string works much the same as before with its comma separation
-- Nested includes are indicated with square brackets "[ ]"
-- The nested include is the value immediately preceding the square brackets
-- The only string is the comma separated string inside those brackets
- Default includes are split between format types when necessary
-- This prevents unnecessary includes from being added on page load
- Available includes are those items which are allowed to be accessible to the user
-- Some aren't because they are sensitive, such as the creator of a flag
-- Some aren't because the number of associated items is too large
- The amount of times the same model can be included to prevent recursions
-- One exception is the root model may include the same model once
--- e.g. the user model can include the inviter which is also the user model
-- Another exception is if the include is a has_many association
--- e.g. artist urls can include the artist, and then artist urls again

app/views/favorite_groups/index.html.erb

@@ -7,7 +7,7 @@
       <%= f.submit "Search" %>
     <% end %>
 
-    <%= table_for @favorite_groups.includes(:creator), width: "100%" do |t| %>
+    <%= table_for @favorite_groups, width: "100%" do |t| %>
       <% t.column "Name", {width: "60%"} do |favgroup| %>
         <%= link_to favgroup.pretty_name, favorite_group_path(favgroup) %>
         <% if favgroup.post_count > CurrentUser.user.per_page %>