Improve railties changelog entry and move latest to the top [ci skip]
Abstract encoding strategy for ActiveSupport::MessageVerifier
[ci skip] Add one more example to routing testing, and highlight association
name keywords
[ci skip] Capybara added to other testing approaches
[ci skip] Improve upon testing tasks guide

Add missing testing tasks and also improve upon tasks descriptions
Add basic tests for ActionDispatch::ExceptionWrapper
exec_prepared is GVL friendly, so lets use it.

also increase the version of pg required so that people will get the
GVL friendly version
[ci skip] Remove deprecated testing tasks

This has changed recently and so rake test:all and rake
test:all:db are deprecated.
[CI SKIP] Corrections to testing guide.

Partially revert https://github.com/rails/rails/commit/c31e638a37946a120f6dbf207127d36beea5ab85.
Build fix when running in isolation

`Computer` class needs to be require

See #17217 for more details
Use `DelegateClass` instead of `SimpleDelegator` for type decorators

There is a significant performance difference between the two. Closes
Simplify and fix grammar

[skip ci]
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
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.