Restore columns dropped by hstore test

Disabling the hstore extension during testing created order dependent
test failures.

respect auto_increment in rename_column for mysql

Fixing some typo(s)/grammar.

Fixing some typos/grammar.

Asia/Ulaanbaatar is incorrect mapping

Fixes #9936

Adds support for concurrent indexing in PostgreSQL adapter

Bump TZInfo version to 0.3.37 based on version v2013b of the underlying tz data.

Adds support for algorithm option in MySQL indexes
Moves USING and algorithm options upstream

The syntax is still specific to the Adapter, so the actual executed string happens
in the corresponding adapter

use relative links inside guides [ci skip]

ActiveRecord::ConnectionAdapters::Column

See
https://github.com/rails/rails/blob/28b8ca766e3e7c6c43d3ae900c99f8377153c62/activerecord/lib/active_record/connection_adapters/column.rb#L16

move mailer testing examples into the testing guide.

Closes #9325.

I adjusted the example and the description in the testing guide and
simply linked from the mailer to the testing guide. This way we don't
have to maintain two separate places.

Add support for pg geometric datatypes point and box

Created a layer of abstraction for the valid type checking in schema dumper. Now, connection handles the check for valid types so that each database can handle the changes individually.

Skipping test for OpenSSL::PKCS5 JRuby

Add a method full_messages_for to the Errors class

Introduce test on Error#full_message for attribute with underscores; Fix...

Fixed typo in railties/test

nil is retuned if cookie is tampered with [ci skip]

if the given key is not found then verifier does raise
`ActiveSupport::MessageVerifier::InvalidSignature` exception
but this exception is resuced and finally nil is returned.

Controller name pluralized

* Fix named route collision in mount test fixture
* Update controller named route precedence test

Transparently upgrade signed cookies when setting secret_key_base

Support .js.coffee views by default

v3 of pull request based on additional feedback from @jeremy