[HttpFoundation] getClientIp is fixed.

The getClientIp now returns ip of the earliest server in a proxy chain when all the servers in the chain are trusted proxies. Before this patch the getClientIp used to return null at such condition.
Some appropriate tests are added.
[Security] Removed unused var
[HttpFoundation] Give control over how session start on demand.

This allows control over how the session start on demand works

0: no start on demand when bags are accessed
1: start session if bags are accessed
2: no start on demand when bags are accessed but still return bag contents
[FrameworkBundle] Add configuration to allow control over session start on demand.

1. Gives user control over session start on demand mode.
2. Re-introduce flag to allow session listener to manually start session.
[FrameworkBundle] Use more sophisticated validation and configuration.
[HttpFoundation][FrameworkBundle] Keep save auto_start behaviour as in 2.2 and make component values consistent with FrameworkBundle's configuration options.
[PropertyAccess] Add objectives to pluralMap
merged branch franmomu/add_objective_to_plurals (PR #7594)

This PR was merged into the 2.2 branch.

Discussion
----------

[PropertyAccess] Add objectives to pluralMap

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7483
| License       | MIT
| Doc PR        |

Commits
-------

6ef92fd [PropertyAccess] Add objectives to pluralMap
merged branch lyrixx/path-10 (PR #7597)

This PR was merged into the 2.2 branch.

Discussion
----------

[Security] Removed unused var

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | I guess
| Fixed tickets | -

Commits
-------

bd26419 [Security] Removed unused var
Update PhpEngine.php

just a minor phpdoc fix
merged branch janschoenherr/patch-5 (PR #7600)

This PR was submitted for the 2.2 branch but it was merged into the 2.1 branch instead (closes #7600).

Discussion
----------

[Templating] Update PhpEngine.php

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

just a minor phpdoc fix

Commits
-------

171b41f Update PhpEngine.php
merged branch denvned/getClientIp-fix (PR #7472)

This PR was merged into the 2.1 branch.

Discussion
----------

[HttpFoundation] getClientIp is fixed.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | no

The getClientIp now returns ip of the earliest server in a proxy chain when all the servers in the chain are trusted proxies. Before this patch the getClientIp used to return null at such condition.
Some appropriate tests are added.

Commits
-------

c4da2d9 [HttpFoundation] getClientIp is fixed.
[Form] DateTimeToRfc3339Transformer use proper transformation exteption in reverse transformation
[HttpFoundation] Fixed bug in key searching for NamespacedAttributeBag

Fixed a bug in NamespacedAttributeBag causing a result to be falsely found when
the last key of the attribute matched the last of the queried name regardless of
if the key did not exist in the search.
Added Tests to demonstrate the issue and resolved by setting keys to null when
iterating through query and returning proper responses in the case that the
given array does in fact not exist.

* Updated Syntax of null checks
* Fixing missing else case for if statement in write context
fixed handling of "0" input on ask
merged branch kipit/ticket_7549 (PR #7623)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #7623).

Discussion
----------

[Console] fixed handling of "0" input on ask

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7549
| License       | MIT
| Doc PR        |

Commits
-------

18a9eaf [Console] fixed handling of "0" input on ask
The /e modifier for preg_replace() is deprecated in PHP 5.5; replace with preg_replace_callback()
merged branch Tatsh/master (PR #7624)

This PR was submitted for the master branch but it was merged into the 2.1 branch instead (closes #7624).

Discussion
----------

[FrameworkBundle] RegisterKernelListenersPass: Removed and replaced use of deprecated preg_match() /e modifier with regards to PHP 5.5

More information: https://wiki.php.net/rfc/remove_preg_replace_eval_modifier

As of beta 2 of PHP 5.5, the above is implemented. Attempting to run the current version of Symfony FrameworkBundle (or 2.1) will cause an `ErrorException`.

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

Commits
-------

c1e98b9 The /e modifier for preg_replace() is deprecated in PHP 5.5; replace with preg_replace_callback()
[Console] fixed handling of "0" input on ask
merged branch kipit/ticket_7549 (PR #7625)

This PR was merged into the 2.2 branch.

Discussion
----------

[Console] fixed handling of "0" input on ask

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7549
| License       | MIT
| Doc PR        |

Commits
-------

302d44f [Console] fixed handling of "0" input on ask