Added method `#eql?` to `ActiveSupport::Duration`, in addition to `#==`.

Currently, the following returns `false`, contrary to expectation:

    1.minute.eql?(1.minute)

Adding method `#eql?` will make this behave like expected. Method `#eql?` is
just a bit stricter than `#==`, as it checks whether the argument is also a
uration. Their parts may be different though.

    1.minute.eql?(60.seconds)  # => true
    1.minute.eql?(60)          # => false
SQLite3Adapter now checks for views in table_exists? fixes: 14041
Propagate test messages through assert_routing helper, Fixes #14908

assert_routing was not raising the message passed into the assertion
violation that it raised. This change propagates messages through
the on_fail error.

This fixes this error:
https://github.com/rails/rails/issues/14908

A test case for this issue is located here.
https://github.com/estsauver/test14908

To see that test case fail in the example app, just run
ruby -Itest test/controllers/guests_controller_test.rb
Update RecordNotFound exception cases to include a message with the
Model that the Record was not found in.
A warning line should look like a warning section

[ci skip]
Cleanup loaded features and constants after dependency tests.
Add a note on custom validation contexts.

The documentation on `:on` for validations was inconsistent, and most
only referenced the `:create` and `:update` contexts. I fixed those to
be consistent with the documentation on `AM::Validations.validates`,
which seemed to have the best docs.

[ci skip]
[ci skip] add guide for ActiveModel::SecurePassword
Updating Associations::Preloader docs

Much of the previous documentation introduced features new in 2011. This
commit refreshes it to provide clearer code examples and spends more
time describing the normal case (preloaded associations) and less time
describing the fallback.

[ci skip]
Roll back open transactions when the running thread is killed.
'Reversible' ->active_record_migrations [ci skip]

Reversible method documentation moved from migrations.md  to active_record_migrations.md
world writable might be a bit too open...
Merge pull request #16818 from phoet/patch-4

world writable might be a bit too open...
'Revert' ->active_record_migrations [ci skip]

Revert method documentation moved from migrations.md  to active_record_migrations.md
Fix for inflector's incorrect camelCase replacement for acronyms

Fixes #8015, #9756.

[Fred Wu & Matthew Draper]
Merge pull request #14911 from estsauver/14908

Propagate test messages through assert_routing helper, Fixes #14908
Message doesn't need to be optional
Add test to assert_recognizes with custom message
:scissors:
Added enable_extension! to helper