Fixed a bug where Rates on a project were being selected by the default

rate finder.  #1921

app/models/rate.rb

@@ -62,7 +62,7 @@ class Rate < ActiveRecord::Base
       return Rate.find(:first,
                        :order => 'date_in_effect DESC',
                        :conditions => [
-                                       "user_id IN (?) AND date_in_effect <= ?",
+                                       "user_id IN (?) AND date_in_effect <= ? AND project_id IS NULL",
                                        user.id,
                                        date
                                       ])

spec/models/rate_spec.rb

@@ -287,7 +287,7 @@ describe Rate, 'for_user_project_and_date (private)' do
   
   it 'should search rates without a project when +project+ is nil' do
     Rate.should_receive(:find).with(:first, {
-                                      :conditions => ["user_id IN (?) AND date_in_effect <= ?",
+                                      :conditions => ["user_id IN (?) AND date_in_effect <= ? AND project_id IS NULL",
                                                       @user.id,
                                                       @date
                                                      ],