Cast number to string in Postgres

fixes #9170
Document change to clashing named route selection from journey commit 98a9802a
Add documentation to ActionDispatch::Request
Http::Headers respects headers that are not prefixed with HTTP_
refactor, `Http::Headers` stores headers in env notation

Also:
cleanup, use consistent syntax for `Http::Header` and test.
allow headers and env to be passed in `IntegrationTest`.

Closes #6513.
`Http::Headers` respects dotted env vars, symbols, headers with numbers.
Merge pull request #9700 from senny/6513_integration_test_headers

rework passing headers and env variables in integration tests
Move some railties changelog entries to the top [ci skip]
Add support for generate scaffold password:digest

* adds password_digest attribute to the migration
* adds has_secure_password to the model
* adds password and password_confirmation password_fields to _form.html
* omits password entirely from index.html and show.html
* adds password and password_confirmation to the controller
* adds unencrypted password and password_confirmation to the controller test
* adds encrypted password_digest to the fixture
Merge pull request #9699 from rubys/scaffold_password_digest

Add support for generate scaffold password:digest

* adds password_digest attribute to the migration
* adds has_secure_password to the model
* adds password and password_confirmation password_fields to _form.html
* omits password from index.html and show.html
* adds password and password_confirmation to the controller
* adds unencrypted password and password_confirmation to the controller test
* adds encrypted password_digest to the fixture
Merge pull request #9690 from trevorturk/upgrade-notes

Rails 4 upgrade notes about clashing named route selection changes
Merge pull request #9698 from garethrees/request_documentation

Add documentation to ActionDispatch::Request
Fix docs: response -> request.

Even though I read it carefully, my brain tricked me. :cry:
Add extra clarifying line in docs. [ci skip]
MOAR cleanups.
Merge pull request #9711 from vipulnsward/moar_cleanups

MOAR cleanups of unused variables.
Handle conditional get in live requests - this will prevent error when using stale on live streams(issue #9636)
Merge pull request #9713 from imanel/live_stale

Handle conditional get in live requests
extract factory method and push common code up to abstract adapter