Revert "Merge pull request #9126 from mbarb0sa/bugfix/json-decoding-in-rails-3-0-stable"

This reverts commit 360af4eba60823c978bd5791d40f85c7c7739c80, reversing
changes made to f93d04677066b74ebb69f57028586126fc19228c.
Merge branch '3-0-stable' of git://github.com/rails/rails into 3-0-stable
Pull in bugfix from upstream for WEB-11626

Remove unicode character encoding from ActiveSupport::JSON.encode

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.

Backport of https://github.com/zbskii/rails/commit/9ace3a8820a5270f9b3f37b593f8bbea3e940f73

Conflicts:

	activesupport/CHANGELOG.md
	activesupport/lib/active_support/json/encoding.rb
	activesupport/test/json/encoding_test.rb

Conflicts:
	activesupport/CHANGELOG.md
Revert "Merge pull request #9210 from dylanahsmith/3-0-mysql-quote-numeric"

This reverts commit 663c9a6335b39f3b63d32619cbb11bece248f982, reversing
changes made to 10513d2eb9892c9e2bfe0ae04c9c16165c5c1544.
Merge branch '3-0-stable' of git://github.com/rails/rails into 3-0-stable

Conflicts:
	activerecord/CHANGELOG