Allow authentication header to not have to specify 'token=' key.

Fixes: https://github.com/rails/rails/issues/17108.
Correct test description for large integer test
Allow habtm class_name option to be consistent with other associations
Simplify and fix grammar

[skip ci]
Merge pull request #17623 from jonatack/patch-8

Simplify and fix grammar [ci skip]
Revert "Improve performance of AR object instantiation"

This reverts commit 8fee923888192a658d8823b31e77ed0683dfd665.

Conflicts:
	activerecord/lib/active_record/attribute_set/builder.rb

This solution sucks, and is hard to actually apply across the board.
Going to try other solutions
Reduce the amount of work performed when instantiating AR models

We don't know which attributes will or won't be used, and we don't want
to create massive bottlenecks at instantiation. Rather than doing *any*
iteration over types and values, we can lazily instantiate the object.

The lazy attribute hash should not fully implement hash, or subclass
hash at any point in the future. It is not meant to be a replacement,
but instead implement its own interface which happens to overlap.
Correctly determine if an attribute is uninitialized

In real usage, we give the builder a types hash with a default value of
`Type::Value.new`. This means we need to explicitly check for the key,
rather than the truthiness of the type to determine if it's a known but
uninitialized attribute
Allow `LazyAttributeHash` to be marshalled

`default_proc` makes a hash unmarshallable, and adds unneccessary
overhead. Since we control all access to the hash, let's just handle it
in that method. This has the side effect of improving performance on
initialization (but not neccessarily on access). We'll need to profile
further once the tests are passing.
Don't freeze the same hash we use for memoization
[ci skip] add "Qu" to Backends Features list
Merge pull request #17626 from y-yagi/queue_adapters_doc

[ci skip] add "Qu" to Backends Features list
Update to Unicode 7.0.0

7.0.0 was released on June 16, 2014

http://unicode-inc.blogspot.com.ar/2014/10/unicode-version-70-complete-text-of.html

ruby bin/generate_tables
Don't let #{application,framework,full}_trace be nil

Those three can be nil when exception backtrace is nil. This happens and
that forced a couple of nil guards in the code. I'm proposing to make
those always return an array, even on nil backtrace.
[CI SKIP] Missing space.
Merge pull request #17636 from gsamokovarov/exception-wrapper-less-nils

Don't let #{application,framework,full}_trace be nil
Merge pull request #17635 from tgxworld/missing_space

[ci skip] Missing space in Active Job guide for referring to Action Mailer
add Nokogiri to docs generation guides
Rename #source_extract to #source_extracts in ExceptionWrapper

It returns multiple source extracts since 1ed264bc. Also cleaned its
result structure, as we no longer need the file in a code extract.
Merge pull request #17637 from gregmolnar/docs

add Nokogiri to docs generation guides [ci skip]