pass default value as argument to fetch

Revert "Documents that ActiveRecord instances also support []/[]= methods for reading/writing attributes"

This reverts commit a49fe6ec.

Reason: The existing doc about using self[:attribute] is clear enough.

This reverts commit b11113f9.

Only write_attribute and read_attribute were documented and there was no mention to this alternative.

The previous example with just_raise_that_exception method
stopped working because MissingTranslation is not an instance of
Exception class any more, but has a +to_exception+ method.

Also the cleaner way is to re-raise only the desired exception, passing
 everything else to the default ExceptionHandler.

 Additionally this re-raising conflicts with Pluralization backend thus
 we have to add a check that certain missing translation keys should
 be ignored allowing the backend to fall back to the default
 pluralization rule.

Fix url_for when options is nil

stringified keys

RouteSet#url_for was modifying the options hash that belong to the
caller

Remove circular require from AS Deprecation, and fix warnings

This reverts commit ddb98755.

Reason: The links must be relative so that they will work both in edge
and stable api sites.

content_tag used instead string for option

mo fasta and mo betta the url_for

removed unnecessary block when using fetch

prevent the cache sweeper ignores NoMethodError

Dependency fix for activesupport

Optimistic locking: lock_version needed type information.

In particular, removed "pages that require to restrict access somehow" and shortened "Action Caching works like Page Caching except for the fact that the incoming web request does go from the webserver to the Rails stack and Action Pack so that before filters can be run on it before the cache is served".

This reverts commit aeb228c5.

Reason: The links are meant to be consumed in the api and not on GitHub.