[ci skip] Fix grammar and sentence framing

Test against Ruby 2.2.4 on Travis.

fix typo in method name [ci skip]

It was changed by mistake at 428d47ad

This reverts commit 4d06ea9a, reversing
changes made to e9d15072.

Reason: This will break oracle-enhanced, see
https://github.com/rsim/oracle-enhanced/blob/3c42131db82b64ac41645db3affc6e4650289df6/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb#L1254

`join_to_delete` is same as `join_to_update`

Add Logger option to disable message broadcasts

All public methods are tasks, so we need to move it to protected
visibility.

This test was failing when run on Windows using PostgreSQL. Depending on
the OS (and 32 vs 64 bit), this type could be a `BigNum`. We could loosen
the assertion to `Numeric`, but if the value is equal to the expected, and
responds to `bitlength` properly, who cares?

When setting the Rails logger to log to STDOUT, it would broadcast the
log twice in development. This adds a setting that will prevent messages
from being broadcast to multiple logs, while still allowing calls to
`#close`, `#level=`, `#progname=`, and `#formatter=` to be broadcasted.

Fixes #14769, #11415

I didn't mean to commit that!

Unlike unix, the TZ variable on Windows does not look at a database. It is
always expected to be in the form {Standard Time
Abbreviation}{UTC-Offset}{Daylight Time Abbriviation}. This changes the
relevant tests to use the Windows form when run from Windows.

[ci skip]

Add `redirect_to_back_or_default`

When this test was run on Windows, the database file would still be in
use, and `File.unlink` would fail. This would cause the temp directory to
be unable to be removed, and error out. By disconnecting the connection
when finished, we can avoid this error.

Use Module.prepend instead of alias_method for Range#to_s

Don't leak Object constants in core_ext/module/qualified_const

"conditionals in the gemfile creates conditional code in the Gemfile.lock.
Since it is checked in the repository I think it is better to avoid it"

bcrypt 3.1.0 doesn't load on Windows. See
https://github.com/codahale/bcrypt-ruby/issues/128
for details.

Applications that use `redirect_to :back` can be forced to 500 by
clients that do not send the HTTP `Referer` (sic) header.
`redirect_back` requires the user to consider this possibility up front
and avoids this trivially-caused application error.

`redirect_to :back` is a somewhat common pattern in Rails apps, but it
is not completely safe. There are a number of circumstances where HTTP
referrer information is not available on the request. This happens often
with bot traffic and occasionally to user traffic depending on browser
security settings.

When there is no referrer available on the request, `redirect_to :back`
will raise `ActionController::RedirectBackError`, usually resulting in
an application error.

`redirect_back` takes a required `fallback_location` keyword argument
that specifies the redirect when the referrer information is not
available.  This prevents 500 errors caused by
`ActionController::RedirectBackError`.

Introduce ApplicationRecord, an Active Record layer supertype

It appears that MRI on Windows can also appear as `:mingw`, if it was
installed via RubyInstaller.

Delete dead code comments

platform `:ruby` is only MRI on Linux or Mac. Windows MRI shows up as
`:mswin` or `:mswin64` depending on if it was installed as 32 or 64 bit. I
am unsure if this will cause conflicts with JRuby on Windows, but I don't
have the means to test this at the moment.

Deprecate passing string to define callback.

Fix a couple of grammatical errors in security.md

Mention the correct way to halt callback chains

The previous title was misleading.

[ci skip]