AS guide: Object#extend_with_included_modules_from has been removed in ccec730d

Fixing up that _delete is no longer used on the form helper for accepts_nested_attributes_for, it is now _destroy

Also created http://github.com/mikel/getting-started-code which is
a copy of all the code in this guide.

Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Signed-off-by: NPratik Naik <pratiknaik@gmail.com>

This reverts commit f936a1f1.

Conflicts:

	activerecord/lib/active_record.rb
	activerecord/lib/active_record/base.rb

Revert "Fixed: #without_typecast should only disable typecasting on the duplicated attributes" [#3387 state:open]

This reverts commit 28319964.

Reason :

  It's not generating attribute methods properly, making object.column 5x slower.