say something about after_(commit|rollback) in callbacks.rb, the fact that their implementation is elsewhere is not important for rdoc purposes

Signed-off-by: NRizwan Reza <rizwanreza@gmail.com>

Signed-off-by: NYehuda Katz <wycats@Yehuda-Katz.local>

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

Changed ActiveRecord to use new callbacks and speed up observers by only notifying events that are actually being consumed.
Signed-off-by: NJoshua Peek <josh@joshpeek.com>

Break up DependencyModule's dual function of providing a "depend_on" DSL and "included" block DSL into separate modules. But, unify both approaches under AS::Concern.

Fixed broken after_save callback; was being called when before_create was canceled or before_update was canceled
Signed-off-by: NMichael Koziarski <michael@koziarski.com>
[#1735 state:committed]

Previously this would have committed the transaction but not carried out save or destroy operation.

[#891 state:committed]
Signed-off-by: NMichael Koziarski <michael@koziarski.com>

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

>> require 'md5'
=> true
>> MD5.new("Asds") == false
TypeError: can't convert false into String
	from (irb):2:in `=='
	from (irb):2
>> false == MD5.new("Asds")
=> false

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

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