Simplify code in AS json encoder
Changed update_record to use prepared statements.
Extract dependency tracking from Digestor
Allow registering custom dependency trackers
Use a thread safe hash
Return an empty array if no tracker is found
Rename ErbTracker to ERBTracker
Register trackers on extensions, not handlers
Merge pull request #8815 from bogdan/simplified-to-json-args

AS JSON encoder: remove monkey patch of Array
Revert "Simplify code in AS json encoder"

This reverts commit 046e27a7338f2961c10e9d133e0e2229b51c2ba8.
Check https://github.com/rails/rails/pull/8815#issuecomment-14026122 for
details.
Raising an ActiveRecordError when one tries to use .touch(name) on a new
object that has not yet been persisted. This behavior follows the
precedent set by update_columns.
Merge pull request #9320 from wangjohn/touch_handling_on_new_instances

Raising an ActiveRecordError when one tries to use touch on a new record object
Added documentation about how touch now throws an error when one tries
to use it on an unpersisted object.
Merge pull request #9246 from Noemj/update_prepared_statements

Changed update to use prepared statements
update 4.0 release notes to reflect the removal of auto explain.
Merge pull request #9411 from senny/add_auto_explain_removal_as_notable_change

update 4.0 release notes to reflect the removal of auto explain.
Keep second fraction when DateTime#change is called.
Merge pull request #9390 from chris-baynes/datetime_sec_fraction

Keep second fraction when DateTime#change is called.
Merge pull request #9409 from wangjohn/adding_documentation_to_touch

Added documentation to touch throwing an error
some minor AR changelog modifications [ci skip]