Change the TimelogController's to/from dates based on the project time entries

Instead of looking for the earliest and latest time entry system wide for the
dates in the form, now TimelogController will only look at the time entries
for the current project (and parent/sub projects).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4087 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/project.rb

@@ -493,6 +493,15 @@ class Project < ActiveRecord::Base
       enabled_modules.clear
     end
   end
+
+  # Returns an array of projects that are in this project's hierarchy
+  #
+  # Example: parents, children, siblings
+  def hierarchy
+    parents = project.self_and_ancestors || []
+    descendants = project.descendants || []
+    project_hierarchy = parents | descendants # Set union
+  end
   
   # Returns an auto-generated project identifier based on the last identifier used
   def self.next_identifier