removed deps checks in unit tests

As Composer is now widely used in the PHP world, having to run composer
install before running the test suite is expected. This also has the
nice benefit of removing a bunch of code, making things easier to
maintain (there is only one place to declare a dev dependency), and
probably more.
Add container aware trait
merged branch endroid/master (PR #8488)

This PR was squashed before being merged into the master branch (closes #8488).

Discussion
----------

Add container aware trait

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

This trait can be used inside a class to make it container aware. As it is not always possible to extend the abstract ContainerAware class, the code for creating a container aware class is usually copied over and over (most of the time unchanged), resulting in a lot of redundant code in your project. As my projects are PHP 5.4 based nowadays, I would like to be able to use a trait in these scenarios to improve my workflow.

Commits
-------

4c9e606 Add container aware trait
optimized circular reference checker
Merge branch '2.2' into 2.3

* 2.2:
  [Security] fixed some phpdoc
  Fixed PHPDoc Blocks
  optimized circular reference checker
  [HttpKernel] changed fragment URLs to be relative by default (closes #8458)
Merge branch '2.3'

* 2.3:
  [Security] fixed some phpdoc
  Fixed PHPDoc Blocks
  optimized circular reference checker
  fixed misleading doc block
  [HttpKernel] changed fragment URLs to be relative by default (closes #8458)

Conflicts:
	src/Symfony/Component/HttpKernel/Fragment/RoutableFragmentRenderer.php
	src/Symfony/Component/HttpKernel/Tests/Fragment/RoutableFragmentRendererTest.php
Replace sha1 and md5 hashing with sha256 algorithm
Use isset() instead of array_key_exists() in DIC
[DependencyInjection] remove code duplication from ContainerBuilder
Merge branch '2.3'

* 2.3:
  Fixing singular form for kisses, accesses and addresses.
  fixed some circular references
  [Security] fixed a leak in ExceptionListener
  [Security] fixed a leak in the ContextListener
  Ignore posix_istatty warnings
  removed unused variable
  [Form] fix iterator typehint
  typos
  Button missing getErrorsAsString() fixes #8084 Debug: Not calling undefined method anymore. If the form contained a submit button the call would fail and the debug of the form wasn't possible. Now it will work in all cases. This fixes #8084
  Use isset() instead of array_key_exists() in DIC
  Fixed annotation
  [BrowserKit] fixed method/files/content when redirecting a request
  [BrowserKit] removed some headers when redirecting a request
  [BrowserKit] fixed headers when redirecting if history is set to false (refs #8697)
  [HttpKernel] fixed route parameters storage in the Request data collector (closes #8867)
  [BrowserKit] Pass headers when `followRedirect()` is called
  Return BC compatibility for `@Route` parameters and default values

Conflicts:
	src/Symfony/Component/Security/Http/Firewall/ContextListener.php
[DependencyInjection] fixed a non-detected circular reference in PhpDumper (closes #8425)

This circular reference cannot be detected by the compiler pass as we
don't check for method arguments there.

The Container itself already detects such circular references at runtime.

So this fix is about circular references that are not detected at
compile time, and are not even detected at runtime because the code that
would cause the detection is never run (generated after a return
statement.)
[DependencyInjection] added tags validation when compiling a container
Merge branch '2.2' into 2.3

* 2.2:
  [HttpKernel] added a check for private event listeners/subscribers
  [FrameworkBundle] fixed registration of the register listener pass
  [Form] Fixed regression causing invalid "WHERE id IN ()" statements
  [DependencyInjection] fixed a non-detected circular reference in PhpDumper (closes #8425)
  [Form] Fixed regression in BooleanToStringTransformer from ed83752
  [FrameworkBundle] removed obsolete code
  [Process] Close unix pipes before calling `proc_close` to avoid a deadlock

Conflicts:
	src/Symfony/Bundle/FrameworkBundle/FrameworkBundle.php
	src/Symfony/Component/HttpKernel/DependencyInjection/RegisterListenersPass.php
	src/Symfony/Component/Process/Process.php
Merge branch '2.3'

* 2.3:
  [HttpKernel] added a check for private event listeners/subscribers
  [FrameworkBundle] fixed registration of the register listener pass
  [Form] Fixed regression causing invalid "WHERE id IN ()" statements
  [DependencyInjection] fixed a non-detected circular reference in PhpDumper (closes #8425)
  [Form] Fixed regression in BooleanToStringTransformer from ed83752
  [FrameworkBundle] removed obsolete code
  [Process] Close unix pipes before calling `proc_close` to avoid a deadlock
  [Process] Fix process merge in 2.3
  [Intl] made RegionBundle and LanguageBundle merge fallback data when using a country-specific locale
Allow null values as tag attributes
Merge remote-tracking branch 'symfony/master' into develop

Conflicts:
	CHANGELOG.md
	src/main/php/ehough/iconic/ContainerBuilder.php
	src/main/php/ehough/iconic/compiler/CheckCircularReferencesPass.php
	src/main/php/ehough/iconic/dumper/PhpDumper.php
	src/main/php/ehough/iconic/loader/YamlFileLoader.php
	src/test/php/Compiler/CheckDefinitionValidityPassTest.php
	src/test/php/ContainerBuilderTest.php
	src/test/php/Loader/IniFileLoaderTest.php
	src/test/php/Loader/XmlFileLoaderTest.php
	src/test/php/Loader/YamlFileLoaderTest.php