A new API method was added to perform redirects:

t3lib_div::redirect($url, t3lib_div::HTTP_STATUS_303);

Status can be any of the following constants:

t3lib_div::HTTP_STATUS_100

t3lib_div::HTTP_STATUS_101

t3lib_div::HTTP_STATUS_200

t3lib_div::HTTP_STATUS_201

t3lib_div::HTTP_STATUS_202

t3lib_div::HTTP_STATUS_203

t3lib_div::HTTP_STATUS_204

t3lib_div::HTTP_STATUS_205

t3lib_div::HTTP_STATUS_206

t3lib_div::HTTP_STATUS_300

t3lib_div::HTTP_STATUS_301

t3lib_div::HTTP_STATUS_302

t3lib_div::HTTP_STATUS_303

t3lib_div::HTTP_STATUS_304

t3lib_div::HTTP_STATUS_305

t3lib_div::HTTP_STATUS_307

t3lib_div::HTTP_STATUS_400

t3lib_div::HTTP_STATUS_401

t3lib_div::HTTP_STATUS_402

t3lib_div::HTTP_STATUS_403

t3lib_div::HTTP_STATUS_404

t3lib_div::HTTP_STATUS_405

t3lib_div::HTTP_STATUS_406

t3lib_div::HTTP_STATUS_407

t3lib_div::HTTP_STATUS_408

t3lib_div::HTTP_STATUS_409

t3lib_div::HTTP_STATUS_410

t3lib_div::HTTP_STATUS_411

t3lib_div::HTTP_STATUS_412

t3lib_div::HTTP_STATUS_413

t3lib_div::HTTP_STATUS_414

t3lib_div::HTTP_STATUS_415

t3lib_div::HTTP_STATUS_416

t3lib_div::HTTP_STATUS_417

t3lib_div::HTTP_STATUS_500

t3lib_div::HTTP_STATUS_501

t3lib_div::HTTP_STATUS_502

t3lib_div::HTTP_STATUS_503

t3lib_div::HTTP_STATUS_504

t3lib_div::HTTP_STATUS_505

More info:
RFC: #9281: Add a method to easily do a HTTP redirect
http://bugs.typo3.org/view.php?id=9281
RFC #11357: Consistency cleanup: Make use of new t3lib_div::redirect function throughout the core
http://bugs.typo3.org/view.php?id=11357

Basic file operation permissions no longer need to be set for individual users, but can be set for a backend group, and will apply to all users in a group.

More info:
RFC #5203: Feature: Implement fileoperation permission configuration from be_groups
http://bugs.typo3.org/view.php?id=5203

The Save & New button allows you to save a record, and be redirected to a form for creating a new one. This saves two clicks for anyone wanting to create two records, one after another. In the past the button was available, but had to be turned on for each specific table. The new default setting is turned on for every table, but can be turned off for specific tables by inserting the following in PageTS:
<code>options.saveDocNew.tablename = 0</code>

Where tablename is the table for which the button should not appear

More info:
RFC: #9183: saveDocNew for all tables except the option is set to 0
http://bugs.typo3.org/view.php?id=9183

A new state available in ext_emconf.php of extensions allows administrators and developers to set extensions to be protected against updates. When an extension is updated, but local version contains changes made by administrators that they don’t want to be overwritten, the system wide update will protect the extension set as excluded from updates.

excludeFromUpdates

To make use of this feature, change the ‘state’ value in $EM_CONF[$_EXTKEY] array to ‘excludeFromUpdates’.

More info:
RFC: #9167: Feature: Mark extension as write protected
http://bugs.typo3.org/view.php?id=9167

New setting allows to control how the internal links to files are targeted. For example,
config.fileTarget = _blank
will open the file in a new window (or tab in most modern browsers).

More info:
RFC: Feature #6626: config.fileTarget for link target on files
http://bugs.typo3.org/view.php?id=6626