Adds STI to Query model. Issue queries are now IssueQuery instances.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@10964 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/functional/issues_controller_transaction_test.rb

@@ -252,7 +252,7 @@ class IssuesControllerTransactionTest < ActionController::TestCase
   end
 
   def test_index_should_rescue_invalid_sql_query
-    Query.any_instance.stubs(:statement).returns("INVALID STATEMENT")
+    IssueQuery.any_instance.stubs(:statement).returns("INVALID STATEMENT")
 
     get :index
     assert_response 500