Return BC compatibility for `@Route` parameters and default values
[BrowserKit] Pass headers when `followRedirect()` is called
[Form] check the required output timezone against the actual timezone
of the input datetime object, rather than the expected timezone supplied
fixed locale of sub-requests when explicitely set by the developer (refs #8821)
Fixed issue #6932 - Inconsistent locale handling in subrequests

The fix consists in passing the locale in the controller reference,
inside the routablefragment renderer.
added a functional test for locale handling in sub-requests
[HttpKernel] added a comment to warn about possible inconsistencies
[Form] Fixed: submit() reacts to dynamic modifications of the form children
Merge branch 'form-submit-2.2' into form-submit-2.3

Conflicts:
	src/Symfony/Component/Form/Form.php
	src/Symfony/Component/Form/Tests/AbstractFormTest.php
	src/Symfony/Component/Form/Tests/CompoundFormTest.php
	src/Symfony/Component/Form/Util/VirtualFormAwareIterator.php
[Form] Removed superfluous reset() call
[Form] PropertyPathMapper::mapDataToForms() *always* calls setData() on every child to ensure
that all *_DATA events were fired when the initialization phase is over (except for virtual forms)
Merge branch 'form-submit-2.2' into form-submit-2.3

Conflicts:
	src/Symfony/Component/Form/Extension/Core/DataMapper/PropertyPathMapper.php
[Form] Removed call to deprecated method
[Form] Removed exception in Button::setData(): setData() is now always called for all elements in the
form tree during the initialization of the tree
[Form] Added a test that ensures that setData() reacts to dynamic modifications of a form's children
fixed request format when forwarding a request
[Yaml] Fix comment containing a colon on a scalar line being parsed as a hash.
merged branch oscherler/yaml-comment-colon-fix (PR #8824)

This PR was squashed before being merged into the 2.2 branch (closes #8824).

Discussion
----------

[Yaml] Fix comment containing a colon on a scalar line being parsed as a hash.

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

Note: I only ran the Yaml Component tests.

This PR fixes a bug in YAML parsing where a comment containing a colon followed by a space, like this:

    foo # warning: this is a scalar with a comment, not a hash

was parsed as a hash, resulting in:

    array( 'foo # warning' => 'this is a scalar with a comment, not a hash' )

instead of:

    'foo'

Commits
-------

4563f1b [Yaml] Fix comment containing a colon on a scalar line being parsed as a hash.
[Form] Extracted ReferencingArrayIterator out of VirtualFormAwareIterator
Merge branch 'form-submit-2.2' into form-submit-2.3

Conflicts:
	src/Symfony/Component/Form/Util/VirtualFormAwareIterator.php