[Process] Prevented test from failing when pcntl extension is not enabled.

SIGTERM constant is only defined if pcntl extension is present. Extension is not needed to use the Process component though.
updated license year
updated license year
Merge branch '2.0' into 2.1

* 2.0:
  updated license year
  Update src/Symfony/Component/HttpFoundation/Response.php
  [Console] fixed unitialized properties (closes #5935)
  [Bundle] [FrameworkBundle] fixed typo in phpdoc of the SessionListener.
  bumped Symfony version to 2.0.21-DEV
  updated VERSION for 2.0.21
  updated CHANGELOG for 2.0.21

Conflicts:
	src/Symfony/Bundle/SwiftmailerBundle/LICENSE
	src/Symfony/Component/Filesystem/LICENSE
	src/Symfony/Component/HttpFoundation/Response.php
	src/Symfony/Component/HttpKernel/Kernel.php
Merge branch '2.1'

* 2.1: (24 commits)
  updated license year
  Update src/Symfony/Component/HttpFoundation/Response.php
  [Form] Fixed inheritance of "error_bubbling" in RepeatedType
  [Form] Fixed DateType when used with the intl extension disabled.
  [HttpFoundation] fix return types and handling of zero in Response
  [HttpFoundation] better fix for non-parseable Expires header date
  Fixed missing plural message in portuguese validator
  Fix Expires when the header is -1
  [DoctrineBridge] Allowing memcache port to be 0 to support memcache unix domain sockets.
  [Console] fixed unitialized properties (closes #5935)
  [Process] Prevented test from failing when pcntl extension is not enabled.
  Revert "[DoctrineBridge] Improved performance of the EntityType when used with the "query_builder" option"
  [Form] Fixed failing tests for DateTimeToStringTransformer.
  [Locale] Fixed the StubLocaleTest for ICU versions lower than 4.8.
  [Bundle] [FrameworkBundle] fixed typo in phpdoc of the SessionListener.
  [Form] Fixed test regression introduced in #6440
  [Tests] Fix namespaces
  Fixed php doc of GenericEvent::__construct
  HttpUtils must handle RequestMatcher too
  use preferred_choices in favor of preferred_query
  ...

Conflicts:
	src/Symfony/Bridge/Propel1/Form/ChoiceList/ModelChoiceList.php