ActiveRecord::Observer was extracted into a separate gem so it
should not be referenced anymore (see https://github.com/rails/rails/commit/ccecab3)

This reverts commit 14fc8b34.

Reason: we need to discuss a better path from this removal.

Conflicts:
	activerecord/lib/active_record/reflection.rb
	activerecord/test/cases/base_test.rb
	activerecord/test/models/developer.rb

This feature adds a lot of complication to ActiveRecord for dubious
value. Let's talk about what it does currently:

class Customer < ActiveRecord::Base
  composed_of :balance, :class_name => "Money", :mapping => %w(balance amount)
end

Instead, you can do something like this:

    def balance
      @balance ||= Money.new(value, currency)
    end

    def balance=(balance)
      self[:value] = balance.value
      self[:currency] = balance.currency
      @balance = balance
    end

Since that's fairly easy code to write, and doesn't need anything
extra from the framework, if you use composed_of today, you'll
have to add accessors/mutators like that.

Closes #1436
Closes #2084
Closes #3807

minor

see: https://github.com/blog/738-sidejack-prevention-phase-2-ssl-everywhere

 - revise introductory text
 - improve examples
 - don't claim that Oracle, SQL Server, or DB2 are supported
 - remove lengthy "simple example"

 - don't reference ancient gem versions
 - don't link to old API doc subdomains
 - point to GitHub instead of RubyForge
 - point to Lighthouse account for support

Signed-off-by: NJoshua Peek <josh@joshpeek.com>

commit e6afd8b2
Author: Xavier Noria <fxn@hashref.com>
Date:   Thu May 8 23:49:36 2008 +0200

    Overall documentation improvement and markup corrections. Zillion changes.

commit 2fead68b
Author: Austin Putman <austin@emmanuel.local>
Date:   Wed May 7 19:35:46 2008 -0700

    Documented class methods on ActionController::Routing.  These are dangerous, and mostly used for testing.

commit f5b84182
Author: Teflon Ted <github@rudiment.net>
Date:   Wed May 7 16:08:49 2008 -0400

    Added explanation about errant inflections not being patched in the future in order to avoid breaking legacy applications.

commit 370f4f51
Author: Sunny Ripert <negatif@gmail.com>
Date:   Wed May 7 14:00:59 2008 +0200

    Applied list conventions in AR::Base

commit 5bd18429
Author: Sunny Ripert <negatif@gmail.com>
Date:   Wed May 7 13:53:35 2008 +0200

    Renamed Options list to Attributes list whenever they weren't option hashes in AR::Base

commit d912bd56
Author: Yaroslav Markin <yaroslav@markin.net>
Date:   Wed May 7 13:50:28 2008 +0400

    Add a filter_parameter_logging usage hint to generated ApplicationController.
    This may help to remind the developer to filter sensitive information from application logs.
    Closes #11578

commit b243de0d
Author: Jack Danger Canty <git@6brand.com>
Date:   Tue May 6 23:39:47 2008 -0700

    doc: disambiguating an example ActiveRecord class

commit f81d771f
Author: Jack Danger Canty <git@6brand.com>
Date:   Tue May 6 23:35:05 2008 -0700

    doc: ActiveRecord::Reflection::AssociationReflection#through_reflection

    Added documentation demonstrating the use of #through_reflection for
    finding intervening reflection objects for HasManyThrough
    and HasOneThrough.

commit ae6b46f0
Author: Cheah Chu Yeow <chuyeow@gmail.com>
Date:   Wed May 7 13:47:41 2008 +0800

    Document AttributeAssignmentError and MultiparameterAssignmentErrors.

commit 8f463550
Author: John Barnette <jbarnette@gmail.com>
Date:   Tue May 6 22:46:44 2008 -0700

    Killing/fixing a bunch of outdated language in the AR README.

commit aca44bcd
Author: Cheah Chu Yeow <chuyeow@gmail.com>
Date:   Wed May 7 13:34:52 2008 +0800

    Make a note about ActiveResource::Timeouterror being raised when ARes calls timeout.

commit 284a930a
Author: Jonathan Dance <jd@wuputah.com>
Date:   Tue May 6 14:58:26 2008 -0400

    improvements to the page caching docs

commit 9482da62
Author: Sunny Ripert <negatif@gmail.com>
Date:   Mon May 5 18:13:40 2008 +0200

    validates_numericality_of() "integer" option really is "only_integer"

commit e9afd679
Author: Sunny Ripert <negatif@gmail.com>
Date:   Mon May 5 12:11:59 2008 +0200

    Harmonized hash notation in AR::Base

commit 67ebf14a
Author: Sunny Ripert <negatif@gmail.com>
Date:   Mon May 5 12:06:19 2008 +0200

    Turned options into rdoc-lists in AR::Base

commit 0ec7c0a4
Author: Marshall Huss <mwhuss@Macbook.local>
Date:   Sun May 4 23:21:33 2008 -0400

    Added information of how to set element_name in the case the user has a name confliction with an existing model
Signed-off-by: NPratik Naik <pratiknaik@gmail.com>

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9226 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

Remove references to ActsAs* from the README now that it's been pulled out into a plugin. Closes #10451 [sjgman9]

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Changed :dbfile to :database for SQLite adapter for consistency (old key still works as an alias) (closes #2644) [Dan Peterson]

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