If you are passed an empty hash, then assign_attributes doesn't need to
do any work and can just return early. This should fix the failing Agile
Web Development tests.

Rails 4.0 has removed attr_protected and attr_accessible feature in favor of Strong Parameters.

begin
  Topic.new("hello" => "world")
rescue ActiveRecord::UnknownAttributeError => e
  e.record # => #<Topic ... >
  e.attribute # => "hello"
end

The Time.time_with_datetime_fallback, Time.utc_time and Time.local_time
methods were added to handle the limitations of Ruby's native Time
implementation. Those limitations no longer apply so we are deprecating
them in 4.0 and they will be removed in 4.1.

attributes

attr_accessible and attr_protected raise an exception pointing to use plugin or new protection model

Cleans up a lot of noise from arguments being passed from one method to
another.

This should make it easier to refactor and improve this code, and remove
complexity with params going around here and there.

Avoid doing a new column lookup for the attribute, since we already have
the column to check for the klass.

Move some methods to the top to better organize them, since they're used
right at the beginning of the multiparameter assignment method chain.

Checking respond_to? incurs overhead, and most of the time when
assigning attributes it will return true. So just handle the
NoMethodError instead.

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

Fixes #6825, adds tests covering cases and error possibilities, also changes SQLite3 driver to correctly generate a time column instead of datetime

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

There are two possible scenarios where the @mass_assignment_options
instance variable can become corrupted:

1. If the assign_attributes doesn't complete correctly, then
   subsequent calls to a nested attribute assignment method will use
   whatever options were passed to the previous assign_attributes call.

2. With nested assign_attributes calls, the inner call will overwrite
   the current options. This will only affect nested attributes as the
   attribute hash is sanitized before any methods are called.

To fix this we save the current options in a local variable and then
restore these options in an ensure block.