[Security] Keep other query string parameters when switching users
duplicated the DebugClassLoader in the Debug component
[HttpKernel] changed fragment URLs to be relative by default (closes #8458)
Use sprintf in "Untrusted Host" and "Invalid Host" exception
fixed misleading doc block
[Debug] fixed typo that prevented smart errors for class not found errors to work
[Debug] fixed unit tests
optimized circular reference checker
merged branch tgabi333/master (PR #8891)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #8891).

Discussion
----------

[DependencyInjection] optimized circular reference checker

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

It is an addtion to my previous PR https://github.com/symfony/symfony/pull/7699

There is no need to check again previously checked sub-trees.

In our tightly coupled services graph, this circular reference check runs avg 1,5ms, before that: 100ms

Commits
-------

67ebf8f optimized circular reference checker
merged branch kriswallsmith/http/misleading-comment (PR #8886)

This PR was merged into the 2.3 branch.

Discussion
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fixed misleading doc block

This doc block does not match what's happening in the code.

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

Commits
-------

4d01e7e fixed misleading doc block
Fixed PHPDoc Blocks

These ```RunTimeExceptions``` are NOT the native ones, therefor the should not be ```\``` in front of them.
merged branch ChristianGaertner/patch-1 (PR #8887)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #8887).

Discussion
----------

[Process] Fixed PHPDoc Blocks

These ```RunTimeExceptions``` are NOT the native ones, therefor the should not be ```\``` in front of them.

| Q             | A
| ------------- | ---
| Fixed tickets | none
| License       | MIT

Commits
-------

26e9717 Fixed PHPDoc Blocks
merged branch fabpot/fragment-urls (PR #8879)

This PR was merged into the 2.2 branch.

Discussion
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Made fragment URLs relative instead of absolute by default

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8458
| License       | MIT
| Doc PR        | n/a

This fixes a regression introduced with the new fragment system where fragment URLs were generated as absolute URLs. As per the ESI spec, there is no need to generate an absolute URL and this can even be problematic when dealing with internal sub-requests in a more "complex" hosting environment.

Commits
-------

91234cd [HttpKernel] changed fragment URLs to be relative by default (closes #8458)
merged branch fabpot/debug-classloader (PR #8870)

This PR was merged into the master branch.

Discussion
----------

duplicated the DebugClassLoader in the Debug component

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

This is a follow-up for #8553.

Commits
-------

d146461 duplicated the DebugClassLoader in the Debug component
[Security] fixed some phpdoc
merged branch vierbergenlars/patch-1 (PR #8854)

This PR was merged into the master branch.

Discussion
----------

[Security] Keep other query string parameters when switching users

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

When switching users, the whole query string gets dropped when redirecting after the switch.
I think only the switch user parameter should be dropped from the query string.

Commits
-------

0a338f5 [Security] Keep other query string parameters when switching users
[Security] added a missing CHANGELOG enrty
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
[BrowserKit] Fixed missing sprintf in InvalidArgumentException