Eager load project associations for notes

This ensures that when viewing an issue each note already has the
associated project, project members, group and group members available.
Since this information is requres for every note this results in quite
the reduction of SQL queries being executed.

app/models/note.rb

@@ -61,7 +61,8 @@ class Note < ActiveRecord::Base
   scope :inc_author, ->{ includes(:author) }
   scope :inc_associations, -> do
-    includes(:author, :noteable, :updated_by, :project)
+    includes(:author, :noteable, :updated_by,
+             project: [:project_members, {group: [:group_members]}])
   end
   serialize :st_diff