Revert "Changelog entry for PR #7560"

This reverts commit ca80067b.
Entry already added in 895233

Changelog entry for PR #7560

Suppress  annoy warning, when executing AR's testcases.

ERB::Util.html_escape encodes single quote as #39. Decimal form has better support in old browsers.

Conflicts:
	activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

Use internal instance variable naming scheme for mounted URL helpers

removed warning: shadowing outer local variable

Raise MissingAttributeError on query methods

When calling a query method on an attribute that was not selected by
an ActiveRecord query, an ActiveModel::MissingAttributeError is not
raised. Instead, a nil value is returned, which will return false once
cast to boolean.

This is undesirable, as we should not give the impression that we know
the attribute's boolean value when we haven't loaded the attribute's
(possibly) non-boolean value from the database.

This issue is present on versions going back as far as 2.3, at least.

set default_headers to nil after use it to avoid order dependent tests

Fixed missing require

Missing require caused fail of guide generation (in
action_dispatch/http/mime_type, line 295, undefined method `ends_with`
for "to_ary":String)
With this fix guides were normally generated

improve AR CHANGELOG [ci skip]

Also just set the hash value instead of merging when it's only one key.

Add a separator option for the excerpt function.

The separation option enable to keep entire words, lines or anything.
To split by line, like github, we can set the separation option as \n.
To split by word, like google, we can set the separation option as " ".
The radius option represent the number of lines or words we want to
have in the result.
The default behaviour is the same. If we don't set the separation
option, it split the text any where.

Dump schema using new style hash

Tests for session handling

Merged in f41dba27
[ci skip]