Remove usage of deprecated _scheme in Routing Component

Instead correctly use the array of schemes from the Route.
Also adjusted the dumpers to dump the correct data.

I extended the tests to not only test the deprecated behavior, but also
the new schemes-requirement.
[Routing] Fix router matching pattern against multiple hosts
bug #9601 [Routing] Remove usage of deprecated _scheme requirement (Danez)

This PR was merged into the 2.3 branch.

Discussion
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[Routing] Remove usage of deprecated _scheme requirement

**This is exact the same commit as it was in #9585, which was not merged due to my fault. Sorry for the noise.**

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #8898, #8176
| License       | MIT
| Doc PR        |

I removed all usages of the deprecated _scheme requirement inside the Routing Component.
Most parts were pretty easy and after multiple refactorings I came up with the solution to have a Route::hasScheme() method and check against this method.

I also checked for performance and after trying in_array, arra_flip+isset and foreach, the last one was clearly the winner.
https://gist.github.com/Danez/7609898#file-test_performance-php

I also adjusted all tests that test '_scheme' to also check the new schemes-requirement.

Commits
-------

557dfaa Remove usage of deprecated _scheme in Routing Component
Merge branch '2.3' into 2.4

* 2.3: (31 commits)
  Fix parent serialization of user object
  [DependencyInjection] fixed typo
  add memcache, memcached, and mongodb extensions to run skipped tests
  [DependencyInjection] Fixed support for backslashes in service ids.
  fix #9356 [Security] Logger should manipulate the user reloaded from provider
  [BrowserKit] fixes #8311 CookieJar is totally ignorant of RFC 6265 edge cases
  [HttpFoundation] fixed constants that do exist in 2.3 (only in 2.4)
  fix 5528 let ArrayNode::normalizeValue respect order of value array provided
  fix #7243 allow 0 as arraynode name
  Fixed issue in BaseDateTimeTransformer when invalid timezone cause Transformation filed exception (closes #9403).
  BinaryFileResponse should also return 416 or 200 on some range-requets
  Do normalization on tag options
  bumped Symfony version to 2.3.9
  updated VERSION for 2.3.8
  update CONTRIBUTORS for 2.3.8
  updated CHANGELOG for 2.3.8
  [Filesystem] Changed the mode for a target file in copy() to be write only.
  [Console] fixed CS
  fixed TableHelper when cell value has new line
  Improved and fixed grammar mistakes. Added pluralized messages
  ...

Conflicts:
	src/Symfony/Component/BrowserKit/Cookie.php
	src/Symfony/Component/HttpKernel/Kernel.php
	src/Symfony/Component/Routing/Matcher/UrlMatcher.php
Merge branch '2.4'

* 2.4: (44 commits)
  [FrameworkBundle] Add missing license headers
  Fix parent serialization of user object
  [DependencyInjection] fixed typo
  added condition to avoid skipping tests on JSON_PRETTY support
  add memcache, memcached, and mongodb extensions to run skipped tests
  [DependencyInjection] Fixed support for backslashes in service ids.
  fix #9356 [Security] Logger should manipulate the user reloaded from provider
  [FrameworkBundle] Added extra details in XMLDescriptor to improve container description
  fixed CS
  Crawler default namespace fix
  [BrowserKit] fixes #8311 CookieJar is totally ignorant of RFC 6265 edge cases
  [HttpFoundation] fixed constants that do exist in 2.3 (only in 2.4)
  fix 5528 let ArrayNode::normalizeValue respect order of value array provided
  fix #7243 allow 0 as arraynode name
  Fixed issue in BaseDateTimeTransformer when invalid timezone cause Transformation filed exception (closes #9403).
  BinaryFileResponse should also return 416 or 200 on some range-requets
  fix deprecated usage and clarify constructor defaults for number formatter
  Bumping dependency to ProxyManager to allow testing against the new 0.5.x branch changes
  Do normalization on tag options
  bumped Symfony version to 2.3.9
  ...