Fixed link for in_place_editor [ci skip]

closes #16512
Point to rubygems instead of Rails GitHub. [ci skip]

The rails repository is not the official plugin anymore
Merge pull request #16458 from chancancode/ar_fix_reserved_inheritance

Fixed issue w/custom accessors + reserved name + inheritance

Conflicts:
	activerecord/CHANGELOG.md
Just like :pool, make sure :checkout_timeout and :dead_connection_timeout are numbers

Using #to_f instead of #to_i because they are specified in seconds instead of milliseconds
Check attributes passed to create_with and where

If the request parameters are passed to create_with and where they can
be used to do mass assignment when used in combination with
Relation#create.

Fixes CVE-2014-3514
Preparing for 4.1.5 release
Merge branch '4-1-5' into 4-1-stable

Conflicts:
	actionmailer/CHANGELOG.md
	actionview/CHANGELOG.md
	activerecord/CHANGELOG.md
	activesupport/CHANGELOG.md
	railties/CHANGELOG.md
Merge pull request #16546 from aditya-kapoor/remove-broken-link

fix broken link to rails blog [ci skip]
Merge pull request #16542 from seamusabshere/numerify-pool-checkout-timeout-from-urls-4-1-stable

Make sure :checkout_timeout and :dead_connection_timeout are numbers
Make ActionMailer::Previews methods class methods.

Conflicts:
	actionmailer/CHANGELOG.md
Merge pull request #16349 from jmcnevin/master

Correctly determine if migration is needed.
Merge pull request #16145 from phoet/patch-2

don't log errors when all is fine
Fixes the digits counter of AS's NumberToRoundedConverter

Zero has one digit, but Math.log10(0) returns -Infinity. The method
needs to special-case zero.

The patch adds a regression test that is not clearly related to the
underlying issue because digit_count is private and has no coverage.
Gray area.

This bug was uncovered by 60062cf.
Merge pull request #16172 from Agis-/hmt_scope_arity

has_many :through with dynamic condition merging
Conflicts:
	activerecord/CHANGELOG.md
Same as f39cb2b except backport friendly

Point release notes to stable branch for list of commits. [ci skip]
Use latest 2.1 version of sprockets-rails
Merge pull request #16649 from Agis-/pg-columns-for-distinct

Fix postgresql adapter #columns_for_distinct trimming whitespace it shouldn't
CHANGELOG & improvements to #16649

* Require either FIRST or LAST qualifier for "NULLS ..."
* Require whitespace before "NULLS ..."
Merge pull request #16664 from rubys/4-1-stable

Use latest 2.1 version of sprockets-rails
Clarify that unknown keys will become HTML attrs

Docs for all the other form tag helpers in this
file already clarify this.

[ci skip]