[HttpFoundation] use different approach for duplicate keys in postgres, fix merge for sqlsrv and oracle
Added phpdoc for Cache-Control directives methods
fixed previous merge
[Doctrine Bridge] fix DBAL session handler according to PdoSessionHandler
bug #11009 [HttpFoundation] smaller fixes for PdoSessionHandler (Tobion)

This PR was merged into the 2.3 branch.

Discussion
----------

[HttpFoundation] smaller fixes for PdoSessionHandler

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10652
| License       | MIT

For both the PdoSessionHandler and DbalSessionHandler
- https://github.com/symfony/symfony/pull/10652#issuecomment-42370425: Transactional DELETE + INSERT does not work as expected
- https://github.com/symfony/symfony/pull/10652#issuecomment-44359784: sqlsrv 2005 does not support the MERGE SQL, and if used it requires an HOLDLOCK
- missing time update for sqlsrv and oracle

Commits
-------

a0e1d4d [Doctrine Bridge] fix DBAL session handler according to PdoSessionHandler
00d707f [HttpFoundation] use different approach for duplicate keys in postgres, fix merge for sqlsrv and oracle
[HttpFoundation] fix switch statement
Merge branch '2.3' into 2.4

* 2.3:
  [Bridge][Twig] Replace deprecated features
  [HttpFoundation] fix switch statement
  [Doctrine Bridge] fix DBAL session handler according to PdoSessionHandler
  fixed previous merge
  Added phpdoc for Cache-Control directives methods
  Remove undefined variable $e
  bumped Symfony version to 2.3.17
  Fix a parameter name in a test
  updated VERSION for 2.3.16
  update CONTRIBUTORS for 2.3.16
  updated CHANGELOG for 2.3.16
  [HttpFoundation] use different approach for duplicate keys in postgres, fix merge for sqlsrv and oracle

Conflicts:
	src/Symfony/Component/DependencyInjection/ContainerBuilder.php
	src/Symfony/Component/HttpKernel/Kernel.php
Merge branch '2.4' into 2.5

* 2.4:
  [Bridge][Twig] Replace deprecated features
  [HttpFoundation] fix switch statement
  [Doctrine Bridge] fix DBAL session handler according to PdoSessionHandler
  fixed previous merge
  Added phpdoc for Cache-Control directives methods
  Remove undefined variable $e
  bumped Symfony version to 2.4.7
  bumped Symfony version to 2.3.17
  Fix a parameter name in a test
  updated VERSION for 2.4.6
  updated CHANGELOG for 2.4.6
  updated VERSION for 2.3.16
  update CONTRIBUTORS for 2.3.16
  updated CHANGELOG for 2.3.16
  [HttpFoundation] use different approach for duplicate keys in postgres, fix merge for sqlsrv and oracle

Conflicts:
	src/Symfony/Component/HttpKernel/Kernel.php