`array_map()` raises a warning when an exception is thrown inside the
callback (see https://bugs.php.net/bug.php?id=55416). To avoid these
warnings, `selectorToXPath()` is applied inside the loop.

This allows the translator and its extensions to be garbage collected
based on the refcount rather than requiring the garbage collector run,
making it much more likely to happen at the end of the
CssSelector::toXPath call.

This PR was merged into the 2.3 branch.

Discussion
----------

unified return null usages

| Q             | A
| ------------- | ---
| License       | MIT

This PR unifies the way we return `null` from a function or method:

 * always use `return;` instead of `return null;` (the current code base uses both);
 * never use `return;` at the end of a function/method.

Commits
-------

d1d569b unified return null usages

* 2.2:
  Fix some annotates
  [FrameworkBundle] made sure that the debug event dispatcher is used everywhere
  [HttpKernel] remove unneeded strtoupper
  updated the composer install command to reflect changes in Composer

Conflicts:
	src/Symfony/Component/Console/Application.php
	src/Symfony/Component/Console/Command/Command.php
	src/Symfony/Component/Console/Input/InputDefinition.php
	src/Symfony/Component/CssSelector/Node/CombinedSelectorNode.php
	src/Symfony/Component/Form/Form.php
	src/Symfony/Component/HttpKernel/Debug/ErrorHandler.php
	src/Symfony/Component/HttpKernel/DependencyInjection/RegisterListenersPass.php
	src/Symfony/Component/HttpKernel/Tests/DependencyInjection/RegisterListenersPassTest.php
	src/Symfony/Component/Locale/Locale.php
	src/Symfony/Component/Locale/README.md
	src/Symfony/Component/Locale/Stub/DateFormat/FullTransformer.php

* 2.1:
  [CssSelector] Fix :nth-last-child() translation
  Fix Crawler::children() to not trigger a notice for childless node

This PR was merged into the 2.3 branch.

Discussion
----------

[CssSelector] Fix :nth-last-child() translation

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8068
| License       | MIT
| Doc PR        | n/a

Commits
-------

2d9027d [CssSelector] Fix :nth-last-child() translation

This PR was squashed before being merged into the master branch (closes #7620).

Discussion
----------

Enforce sprintf for exceptions

| Q             | A
| ------------- | ---
| Bug fix?      |no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | [yes|no]
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/pull/2483

Changed format of exceptions which concatenate strings as follows

````
throw new \Exception('The '.$something.' needs the '.$foobar.' parameter');
````

to

````
throw new \Exception(sprintf('The %s needs the %s parameter', $something, $foobar));
````

This follows discussion on mailing list: https://groups.google.com/forum/?fromgroups#!topic/symfony-devs/tecj3UOAueM

Unit test results are pending...

Commits
-------

e655120 Enforce sprintf for exceptions