`rails new --edge` should use the '4-1-stable' branch

See 14ef77ba
Merge pull request #14100 from chancancode/rails_new_edge

`rails new --edge` should use the '4-1-stable' branch
[ci skip] Close the meta tag with '/>' instead of '>'

This change fixes the 42 instances of `end tag for "meta" omitted, but
OMITTAG NO was specified` error message that comes up when the full
railsguides are validated.

Full error list at
https://gist.github.com/prakashmurthy/9086679.
Pointing to latest guides [ci skip]
Merge pull request #14124 from arthurnn/fix_14116

Fix collection proxy exists? regression
Revert "context in validation goes through has many relationship"

This reverts commit 5e3d466d52fa4e9a42c3a1f8773a7c31da875e48.
adding a test for #14106
releasing Rails no longer needs triggering docs generation by hand [ci skip]

GitHub is now able to notify tag creation, I have configured the webhook
for the docs server to receive that event. Therefore, we no longer need
to trigger docs generation manually when releasing.
Revert "Only lookup `config.log_level` for stdlib `::Logger`. Closes #11665."

This reverts commit e0a521cfcd13e4d1f0ae8ab96004289e1c020f71.

Conflicts:
	railties/CHANGELOG.md

We expect loggers to quack like stdlib logger. If log4r needs different
level= assignment, using a Logger-quacking wrapper is the way to do it.

Fixes #14114.
Merge pull request #14140 from WojtekKruszewski/optimize_foreign_key_for

Prevent foreign_key_for? from evaluating all attributes
Add tests for default scope behaviour change

See #13875
Go with #presence_in instead of #present_in -- it doesnt sound quite as good, but the closer relationship to #presence over #present is ultimately worth it
Wups, committed the Gemfile change by mistake
Introduce `Rails.gem_version`

This method returns a `Gem::Version` object, which is useful when
performing a comparison between versions. This was originally
introduced as `.version` by @charliesome in #8501, but got reverted in
#10002 since it was not backward compatible.

Also, updating template for `rake update_versions`.