"Predicates in Rails rely on standard Ruby semantics for boolean values
and guarantee no singletons whatsoever." - @fxn

Remove useless conditional.

There was an example here that mentioned reload_plugins?
but it was deleted. This commit puts another example back.

fix HashWithIndifferentAccess.[] method

ActionController caching small String#split optimization

Reason: This commit changes code that was committed some year
and a half ago. The original code is an ordinary predicate
that delegates straight to a boolean operator with no further
unnecessaru adorments, as clearly explained in #5329.

This change also may confuse users who may now believe they can
rely now on singletons, while predicates in Rails rely on
standard Ruby semantics for boolean values and guarantee no
singletons whatsover.

This reverts commit 6349791d.

Conflicts:
	guides/source/ruby_on_rails_guides_guidelines.textile

removed warning: shadowing outer local variable - exception

Return an actual boolean from xml_http_request?

fixes #5521

Fix environment support for rails server, and match interface of rails console

Remove code duplication

use the new scope syntax on the tests to avoid DEPRECATION WARNINGS.

Remove ActiveModel::Naming#partial_path

Before it was handled by Proc.bind, but since Proc.bind has been
deprecated, this is no longer the case and returned handler
needs to match rescuer.

Fixed missing space bug introduces in rails/rails@9299bfd

deprecate Proc#bind that can cause symbol memory leak

rails server takes `-e` as an argument to specify RAILS_ENV, rails console currently does not have the same interface. This commit fixes this disparity so developers can manually specify `RAILS_ENV` or can pass in an environment with a `-e`.

Adding documentation for ActiveRecord::Base.abstract_class to clarify a particular usecase for this feature (to allow you to use inheritance in ActiveRecord without using the STI table name

Avoid another blank line in generated migration and remove assertion as per @spastorino request