Merge branch 'master' into adequaterecord

* master:
  add services: memcache to travis
  The `source` option for `has_many => through` should accept String values.

.travis.yml

@@ -1,3 +1,4 @@
+services: memcache
 script: 'ci/travis.rb'
 before_install:
   - travis_retry gem install bundler

activerecord/lib/active_record/reflection.rb

@@ -621,7 +621,7 @@ module ActiveRecord
       end
 
       def source_reflection_name # :nodoc:
-        return @source_reflection_name if @source_reflection_name
+        return @source_reflection_name.to_sym if @source_reflection_name
 
         names = [name.to_s.singularize, name].collect { |n| n.to_sym }.uniq
         names = names.find_all { |n|

activerecord/test/models/tag.rb

@@ -3,5 +3,5 @@ class Tag < ActiveRecord::Base
   has_many :taggables, :through => :taggings
   has_one  :tagging
 
-  has_many :tagged_posts, :through => :taggings, :source => :taggable, :source_type => 'Post'
+  has_many :tagged_posts, :through => :taggings, :source => 'taggable', :source_type => 'Post'
 end