The log output used to be confusing in situation where type casting has
"unexpected" effects. For example when finding records with a `String`.

BEFORE:

irb(main):002:0> Event.find("im-no-integer")
D, [2013-11-09T11:10:28.998857 #1706] DEBUG -- :   Event Load (4.5ms)  SELECT "events".* FROM "events" WHERE "events"."id" = $1 LIMIT 1  [["id", "im-no-integer"]]

AFTER:

irb(main):002:0> Event.find("im-no-integer")
D, [2013-11-09T11:10:28.998857 #1706] DEBUG -- :   Event Load (4.5ms)  SELECT "events".* FROM "events" WHERE "events"."id" = $1 LIMIT 1  [["id", 0]]

This saved about 46 array allocations per request on an extremely simple
application.  The delegation happened in the notification subsystem
which is a hotspot, so this should result in even more savings with
larger apps.

Squashed commit of the following:

commit 41eef0d1479526f7de25fd4391d98e61c126d9f5
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Wed Nov 6 16:32:31 2013 -0800

    speed up notifications

commit 586b4a18656f66fb2c518fb8e8fee66a016e8ae6
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Wed Nov 6 16:31:05 2013 -0800

    speed up runtime registry methods

commit b67d074cb4314df9a88438f785868cef77e583d7
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Wed Nov 6 16:28:12 2013 -0800

    change method name and make it public

refs #11561 #12700

This allows to assign both `String` and `Symbol` values to the enum
without having to call `to_sym`, which is a security problem.

Commit 6e4a810f changed the implementation
from class_eval to define_method, but missed the access to the constant
versus the access to the constant name.

Reuse the already existing logic used for grabbing this information from
the updated columns.

https://github.com/rails/rails/commit/db41eb8a6ea88b854bf5cd11070ea4245e1639c5#commitcomment-4502683

Revert "ActiveRecord::Base#<=> has been removed.  Primary keys may not be in order," -- will be replaced with a check to ensure that the keys used for comparison are integers, and only fail if they are not.

This reverts commit 6256734e.

Conflicts:
	activerecord/CHANGELOG.md

Extend ActiveRecord::Base#cache_key to take an optional list of timestamp attributes of which the highest will be used.

Added ActiveRecord::Base#enum for declaring enum attributes where the values map to integers in the database, but can be queried by name

was using nullify strategy

This caused a regression in applications trying to upgrade.

Also if the user set the dependent option as destroy he expects to get
the records removed from the database.

Same as 4d4ff531

The use of `store` on Hstore fields (for instance) is not needed
because serialization aimed to interact with Ruby objects and not
with provided field types

Fixes: #12242, #9517, #10240

Add a note about ensuring the version is right for the adapter (since you might well have specified the right gem, but locked it to too low of a version)

added schema_migrations_table_name to ActiveRecord::Base in order that the name of the schema migrations table can be configured.

consolidated test_schema_migrations_table_name tests

Added changelog entry

edited changelog

removed commented lines

removed reader

ensure the schema migrations table is reset at end of test

added entry to configuration guide

guides typo and changelog order

Fixed syntax error on `after_commit` docs

See also commit 5ac2341f

Fixes: #12640

This is necessary because as of 5ac2341f `hstore` columns are always stored
as `Hash` with `String` keys. `ActiveRecord::Store` expected the attribute to
be an instance of `HashWithIndifferentAccess`, which led to the bug.