Replace AR with ActiveRecord to make it more readable [ci skip]

activerecord/lib/active_record/inheritance.rb

@@ -82,7 +82,7 @@ module ActiveRecord
       # Returns the class descending directly from ActiveRecord::Base, or
       # an abstract class, if any, in the inheritance hierarchy.
       #
-      # If A extends AR::Base, A.base_class will return A. If B descends from A
+      # If A extends ActiveRecord::Base, A.base_class will return A. If B descends from A
       # through some arbitrarily deep hierarchy, B.base_class will return A.
       #
       # If B < A and C < B and if A is an abstract_class then both B.base_class

activerecord/lib/active_record/model_schema.rb

@@ -240,7 +240,7 @@ module ActiveRecord
       end
 
       # Returns a hash where the keys are column names and the values are
-      # default values when instantiating the AR object for this table.
+      # default values when instantiating the Active Record object for this table.
       def column_defaults
         load_schema
         _default_attributes.to_hash

guides/source/3_2_release_notes.md

@@ -327,7 +327,7 @@ Active Record
 
 * Implemented `ActiveRecord::Relation#explain`.
 
-* Implements `AR::Base.silence_auto_explain` which allows the user to selectively disable automatic EXPLAINs within a block.
+* Implements `ActiveRecord::Base.silence_auto_explain` which allows the user to selectively disable automatic EXPLAINs within a block.
 
 * Implements automatic EXPLAIN logging for slow queries. A new configuration parameter `config.active_record.auto_explain_threshold_in_seconds` determines what's to be considered a slow query. Setting that to nil disables this feature. Defaults are 0.5 in development mode, and nil in test and production modes. Rails 3.2 supports this feature in SQLite, MySQL (mysql2 adapter), and PostgreSQL.
 

railties/lib/rails/tasks/engine.rake

@@ -40,7 +40,7 @@ namespace :db do
   desc "Rolls the schema back to the previous version (specify steps w/ STEP=n)."
   app_task "rollback"
 
-  desc "Create a db/schema.rb file that can be portably used against any DB supported by AR"
+  desc "Create a db/schema.rb file that can be portably used against any DB supported by Active Record"
   app_task "schema:dump"
 
   desc "Load a schema.rb file into the database"