Conflicts:
	actionpack/lib/action_view/helpers/form_helper.rb
	railties/lib/rails/info_controller.rb

This reverts commit d1e70cb7.

This reverts commit 2f0311d7.

This reverts commit db9b619f.

This reverts commit e5f8b2be.

This reverts commit 6e72099a.

Reason: Feel that this isn't the right place.

The encoding scheme (e.g. ☠ -> "\u2620") was broken for characters
not in the Basic Multilingual Plane.  It is possible to escape them
for json using the weird encoding scheme of a twelve-character
sequence representing the UTF-16 surrogate pair (e.g. '𠜎' ->
"\u270e\u263a") but this wasn't properly handled in the escaping code.
Since raw UTF-8 is allowed in json, it was decided to simply pass
through the raw bytes rather than attempt to escape them.

Mysql2 doesn't support binds, which means no binds payload is set when
logging, so the logic to render binary data differently here doesn't work.

Introduced in 99d142a9.

Do not log the binding values for binary columns.

This reverts commit 6bdc0462.

This has been reverted because https://github.com/rails/rails/commit/8554537e48d6ed18ef08cb3ac0a9da96ac3c5cd6

This reverts commit ae68fc38, reversing
changes made to 0262a18c.

See here: https://github.com/rails/rails/pull/8499#issuecomment-11356417

They tend to be large and not very useful in the log.

Thread safety improvements

Fix for has_many_through counter_cache bug

Counter caches were not being updated properly when replacing
has_many_through relationships.

This commit fixes reported issue #7630 in which counter
caches were not being updated properly when replacing
has_many_through relationships

Removed :if / :unless conditions to fragment cache in favour of *cache_i...

cache_if(condition, option, &block) and cache_unless(condition, option, &block).

In the PR #8371 was introduced  conditional options :if and :unless in
the cache method.

    Example:

      <%= cache @model, if: some_condition(@model) do %>
        ...
      <%end%>

This is a good feature but *cache_if* and and *cache_unless*
are more concise and close to the standard of rails view helpers
(ex: link_to_if and link_to_unless).

    Example:

      <%= cache_if condition, @model do %>
      ...
      <%end%>

Remove all the old url helper methods when clear! is called on the
route set because it's possible that some routes have been removed.

This doesn't actually remove old url helper methods as they are
defined in a different module.

This reverts commit 96bcef94.

Conflicts:
	actionpack/CHANGELOG.md

Related to the HTML route inspector changes:
ae68fc38

Summary of the changes:
 * Add thread_safe gem.
 * Use thread safe cache for digestor caching.
 * Replace manual synchronization with ThreadSafe::Cache in Relation::Delegation.
 * Replace @attribute_method_matchers_cache Hash with ThreadSafe::Cache.
 * Use TS::Cache to avoid the synchronisation overhead on listener retrieval.
 * Replace synchronisation with TS::Cache usage.
 * Use a preallocated array for performance/memory reasons.
 * Update the controllers cache to the new AS::Dependencies::ClassCache API.
   The original @controllers cache no longer makes much sense after @tenderlove's
   changes in 7b6bfe84 and f345e238.
 * Use TS::Cache in the connection pool to avoid locking overhead.
 * Use TS::Cache in ConnectionHandler.

Since Rails 3.1, change method is preferred for writing
migrations. Updated the example, because that command
would generate migration with change method.

https://github.com/lifo/docrails/commit/55a2820cc6d33e96b8d1b64b38b033913058dce4
messes up
https://github.com/lifo/docrails/commit/cfd324b4b68469ba3188e4b7ba8586e59b239693

Hopefully there is other stuff lost in translation...

I was trying to use those files without Rails and that require was
missing.

Add migration examples to Association Basics

[ci skip]

Output routes in :html format

This is apparently used by the railtie to setup the app helpers paths
correctly between initializers. I'll need to check it further.

Don't include debugger gem if jruby is used since it doesn't work on jruby. [ci skip]

* Avoid calling class_eval when not needed
* Remove helpers_path attr accessor, it's defined as a class attribute a
  few lines later
* Avoid creating extra arrays when finding helpers, use flat_map and sort!
* Remove not required refer variable when redirecting :back

Recognize migrations, in folders containing numbers and 'rb'

Closes #8492